The Process is easy as there are three main requirements for a Will to be legal.
It must be in writing. Telling a friend or anyone else what your intentions are is certainly not good enough.
You must sign it.
When you sign it, there must be at least two other people present to witness your signature and vice versa.
In addition you should date it, specify that previous wills (if any) are 'revoked' (cancelled), and choose who you would like to carry out your wishes ( executor(s).
Make sure you give sufficient information on particular possessions intended for particular individuals, to ensure that they can be identified. 'To my Carer, the picture she likes in the living room', for instance, would not surfice if there are six pictures and three different Carers.
You should give details of the beneficiaries, including their full names including aliases and the address of each of them, if possible.
Generally, your will should be clear on what will happen to a bequest if the beneficiary pre-deceases you. For example, whether it lapses, goes to their children (and in what proportions), or goes to someone else instead or just goes back into the estate. When you leave a bequest to a class of people, such as 'my grandchildren living at my death', be specific as to whether that includes unborn children, so pregnancies are covered. And you should say where you want the 'residue' (everything left over, once the specific bequests have been satisfied) to go.
Finally, it is desirable to leave details of your possessions (or at least, an indication of where such details can be found) with your will. I have car so will travel to you at a time and place that is convenient for both.