Although there is no legal requirement for a Will to be drawn up or witnessed by a solicitor we recommend that unless your Will is very simple indeed you should consult a solicitor as to its contents.
There is nothing to stop you making a Will yourself but, unfortunately, due to the complexity of the laws relating to Wills (and also the fact that you will not be around when the Will comes into effect!) it is very easy to make a mistake in drafting your Will, some of the most common mistakes in home made Wills are as follows:-
Any solicitor you instruct will be legally qualified and will carry compulsory indemnity insurance covering you against any mistakes the solicitor may make. The solicitor will also have considerable experience in this area of law and be able to advise you of its technicalities in a simple and straightforward way.