There is no need for a will to be drawn up or witnessed by a solicitor. If you wish to make a will yourself, you can do so.
However, you should only consider doing this if the will is going to be straightforward.
However, it is easy to make mistakes and, if there are errors in the will, this can cause problems after your death. Sorting out misunderstandings and disputes may result in considerable legal costs, which will reduce the amount of money in the estate. Mistakes can also mean an increased Inheritance Tax Bill and at worst render a will invalid.