If you let someone else choose things for you, it makes the decision process easier and quicker, but you’re never going to get exactly what you want. If you opt for a box of chocolates, for example, there’s bound to be some unpopular flavour scudding around at the bottom.

So if you really want to get exactly what you’re after, you need to do the selecting yourself, whether that’s picking and mixing your own chocolates, or choosing your own individual savings accounts investments through a self-select ISA.

These can offer the full range of ISA-able investments, including single company shares, unit trusts, investment trusts, real estate investment trusts, gilts, cash, exchange-traded funds, structured products and cash funds. Peter Howard, product manager for TD Waterhouse, says, ‘The only commonly traded shares in the UK you can’t hold are those listed on AIM and PLUS (formerly Ofex), because they are banned under the ISA rules.’

Maximum flexibility
You can make up your ISA allowance with any combination of these, and buy and sell them within the self-select ISA wrapper whenever you want to. It is by far the most flexible kind of ISA, and gives you free reign to pick exactly what you want.

But before you start choosing your investments, you need to find the right ISA first. There are scores of different ones on the market, available from small, local stockbrokers, larger national chains, and internet brokers. So it is worth looking into the details of each offering to identify which one is right for you.

Your first consideration should be whether a provider offers all the investment options you are looking for. Some, for example, allow investment on up to 20 international exchanges. Others offer trading in most popular foreign shares, and others limit investors to the UK for direct shareholdings.

Also check the range of funds available. Some will offer all the funds in the investable universe, while others use a fund supermarket platform. These have a huge range, but some may not have everything, so it is worth checking that their range is suitable for you.

Ben Lundie, head of Vantage development at Hargreaves Lansdown, points out, ‘Providers may be restricted to certain “buy” lists or fund groups depending on the platform they use. Cofunds has 70 or 80 fund groups and if you want something outside that range you are restricted.’ Others, such as E*trade, are designed for direct equity investments, and don’t offer access to funds at all.

Some self-select providers offer products that are specific to themselves. Barclays Stockbrokers has structured products that are listed on the stock exchange, so it offers those through its self-select ISA. It also has its own brand of exchange-traded funds, iShares, listed on the stock market, so it sells those through its ISA too.

Many ways to invest
The next consideration is how you want to buy and sell your shares. Things have changed in the past few years, and nowadays almost all providers will offer online dealing. This tends to be the cheapest option. However, most will offer access to telephone dealing services. You will pay more for this service – in some instances 30 per cent more - but if you are more comfortable dealing with someone over the telephone, it is worth making sure your broker offers this service.

If you plan to operate online, explore the website to see how easy it is to use. Making trades, checking statements, finding your trading history and account activities should all be quick and easy to do. If you are struggling to find a vital function, it is likely to prove highly frustrating in the long run.

Next you’ll need to think about charges. Trading charges have fallen dramatically with the advent of online brokers, but they still vary.  They are also structured in different ways. Some charge a flat fee: Selftrade has one fee of £12.50 per trade, while E*trade has a standard online dealing charge of £8.95. Others charge a fee according to tiers: the higher the sum you are trading, the more you pay. While still more charge a percentage of whatever you are dealing (usually with a minimum attached). The Share Centre charges one per cent, with a minimum of £7.50 per trade.

Your decision depends on the kind of trades you plan to make. If you expect to deal in relatively small amounts, your cheapest option may be a percentage arrangement with a low minimum, such as the Share Centre. If you intend to trade more than around £100 at a time, then a single flat fee is worth considering, such as iDealing at £9. Even if you are starting with relatively modest amounts, if you have big ambitions, the flat fee approach offers the security that if you need to deal larger amounts later your costs won’t increase exponentially.

Lower costs for regular trades
Some brokers will offer special dealing charges for those who trade regularly. Those who deal more than five times a month through Barclays Stockbrokers see their online charge fall from £12 per trade to £7.50. Very frequent traders can expect even lower charges, such as £6.50 with Hoodless Brennan. So if you are expecting to be an active trader it is worth considering this kind of offer.

However, check how often you would need to trade to take advantage of these deals. E*trade requires 30 deals a quarter to qualify for its lower online dealing charges, while some require daily trading, which only suits a certain kind of investor.

Some brokers offer bulk trades, which collect deals and make them when they have enough to make it cost effective. The charges for this are lower than standard charges – but you will lose the immediacy of your trade. If you are buying and holding for the long term, a week’s delay in selling isn’t going to be the end of the world, but for more active traders, this could be too high a price to pay.

The other key charge is the administration fee. Some charge a flat fee, such as E*trade at £30 a year, iDealing at £20 a year, or Barclays Stockbrokers at £30 a year for anything up to £7,500 and £50 a year for anything more. Others charge a percentage of your holding, subject to minimum and maximum charges. Hargreaves Lansdown charges 0.5 per cent a year, up to a maximum of £200.

This works out as relatively low cost on one year’s ISA allowance. But it is worth considering what will happen to that charge if you add further years’ allowances, or as your investments grow.  You need to consider what happens if you decide to consolidate older PEPs into the account under new rules from April, which could push the cost of a percentage deal up dramatically.

Some brokers don’t charge an administration fee at all. TD Waterhouse only charges one on ISAs worth less than £3,600. These deals could help you save substantially, but it is important to check the overall cost to ensure you are not simply paying more for each trade in return.

Other associated costs
The charges for holding assets other than shares can also differ. Self-select ISAs with a fund supermarket attached, or as part of the product, will offer fund supermarket-style savings on any funds bought through the platform. Hargreaves Lansdown offers savings on initial charges of up to 5.5 per cent, and an annual loyalty bonus, which returns part of the annual charge to the investor.

Some, such as Barclays Stockbrokers, don’t charge an admin fee if you are only holding funds, and some charge just the admin fee on the portion you are holding in shares. So it is worth looking into this area.

There is a host of other charges too. Some providers will charge for paper statements, wire transfers, duplicate contract notes and tapes from telephone deals. Most are pretty similar, and none will break the bank, but it is worth being aware of all these charges before you go in, to ensure you aren’t signing up to anything that could prove costly later.

You also need to check the rules on closing the account or transferring out. Some, such as E*trade, will charge you for each holding you transfer, and some will charge an overall fee. These aren’t necessarily particularly punitive, but it is worth being aware of what they are likely to be in advance.

You will also face statutory charges regardless of which self-select ISA you choose. These include stamp duty of 0.5 per cent on any direct share purchase, and a levy of £1 on any transaction over £10,000.

If you’re planning to switch an existing ISA into a self-select wrapper, you’ll need to check the rules for that too. Some providers will cover the fee from the firm you are transferring from. Barclays Stockbrokers, for example, will pay up to £150 per account in transfer costs, up to a maximum of £500. Others, however, won’t take transfers in.

The question of cash
Beyond charges, there are other important considerations. At the moment, it is vital to know your provider’s approach to cash holdings. There are investors who will want
to get a self-select ISA so they have reserved their allowance, but don’t really want to be in the market at the moment.

Strictly speaking, HMRC doesn’t like cash being held in self-select ISAs, and has specified that this is allowed on a short-term basis only. As a result, most providers will write to investors monthly or quarterly if they have cash held in their account. However, they won’t consider it unreasonable if an investor chooses to stay out of the market for anything between three and 12 months.

If you expect to be out of the market at any stage, it is worth checking what the rate paid by self-select ISA providers is on cash, because rates vary tremendously. TD Waterhouse offers just 0.5 per cent, as it wants to encourage investors into stocks and shares, and points out that there are other low-risk options available through the ISA, such as cash funds and bond funds. Others, such as Hargreaves Lansdown, will offer something relatively competitive, because some people who hold cash for 12 months or longer. At the moment, it offers 5.5 per cent fixed for three months.

It is worth looking at the other services your provider offers alongside its ISA. Straightforward execution-only brokers will tend to equip you with information and resources to help you make your own decisions. These can include online information on funds, real-time company news, fundamental data, and charting tools.

Tony Celentano, sales and business development manager for E*trade, says, ‘We offer easy reference tools to enable investors to compare their stock to the sector or to the index, or to research company news or data. For more active traders we offer Reuters news, streaming prices, and technical charting as well.’

Getting advice
Others will offer advice-based tools. Hargreaves Lansdown has a Wealth 150, which is a list of the firm’s favourite funds, as identified by its research team. Alternatively, providers may simply offer advice.

Gavin Oldham, chief executive of stockbroker The Share Centre, says, ‘Advice is an optional extra, but we don’t charge anything for it. Anyone with an ISA has access to the investment advice department. If you have an idea on a sector, for example, they may give you their view and point you in the direction of stocks.’

The final choice, of course, remains in the investor’s hands. The right self-select ISA will give you the range and the flexibility you need to make the right choice. This will come at the minimum cost to you, and with the tools and support you need.

Of course, these things aren’t set in stone. If a self-select ISA is right for you today, there is no guarantee that it always will be, so it is worth checking regularly to make sure it suits your needs. If you find yourself fully invested in funds you may find yourself better off in a fund supermarket. All this choice and flexibility is great, but it comes
at a cost, so if you don’t use it and you are still paying for it, you have ended up with the worst deal of all.