Self-select ISAs, enable you to hold a wide variety of investments ranging from UK and overseas shares to exchange-traded funds and permanent interest-bearing shares (PIBS).

If you have existing shareholdings, it is worth considering transferring them into a self-select ISA. Although it is not normally permitted to switch shares directly into an ISA, many providers offer 'Bed and ISA' arrangements at this time of year, which means they will sell your shares and buy them back inside an ISA for you, but will only charge you for one of the deals.

Self-select ISAs are offered by a variety of providers from traditional stockbrokers to purely online brokers. Financial advisers also offer them. Choosing between them will partly depend on how wide an investment choice you want.

Self-select ISAs are not just for those who want to invest in shares, they are also useful for investors who want to hold a combination of investment funds and shares.

The low dealing charges on many self-select ISAs mean that it is possible to have a spread of holdings even within the £7,000 limit.

Because they can hold all sorts of investments, one of the attractions of self-select ISAs is that they allow you to consolidate all your past ISAs and PEPs in one place.

You can often transfer shareholdings and investment funds from previous ISAs into a self-select ISA 'in specie', so you won't have to cash them all in, though there will normally be an administration charge for each stock transferred and there may also be a closing fee.

You need to try and get a spread of sectors, so if you hold privatisation or demutualisation shares in one or two sectors, look for businesses operating in other areas.

You can also hold foreign shares. Not all ISA providers will allow this, but many will, providing settlement is possible via Crest (the London Stock Exchange's electronic settlement system, which is the case nowadays with many North American and European shares).

Self-select ISAs tend to be execution-only, so you will be left to make the investment decisions yourself. But providers will often offer access to helpful information and research via their websites. They may also provide guidance on basic investment techniques.