It is and should be a simple process if you have the basics right, if one is not aware of the full implications it is much better to hire the services of a professional. Their services do not come cheap as this is a specialised area. Very few individuals require offshore companies to limit or eliminate their tax liabilities, there are simpler ways.
Spare a moment to consider the following:
You have made £75,000 profits (after deduction of all expenses etc.) for the financial year ended 5 April 2004, of this the Inland Revenue want 40% (it might not be but, we will assume it is). Your tax bill is £30,000 and assuming your accountant files your Return between August and September 2004, the Inland Revenue will send you a bill within two months. The tax is not paid until 2005; in effect, you have been given an interest free loan by the Inland Revenue. You can either keep the money in the bank or use it to trade etc. pending payment. Let us assume that one chooses to trade with the £30,000 and makes a return of 2.5% (£750) per week on the money; it means that one has doubled the money by the time the payment is due.
On this basis, one would have paid the rather large tax bill without any hassle and made money in the process. Not bad.