Making a Will is not about wealth it is about making sure that what you want to happen to your estate does happen. It gives you the opportunity to specify such things as who will administer your estate, who will care for your children and who will receive specific items of your property.
Other occasions include the birth of a child and if you inherit or win large sums of money.
By far the best way of dealing with revocation of a will is by making a fresh one. You can make as many wills as you wish during your lifetime but it is essential that it is possible clearly to identify which is the last one.
Most solicitors will retain photocopies of your earlier wills with your current one for evidential purposes. If, for example, the last will is challenged, copies of the earlier ones may show a clear pattern of testamentary gifts. This may go a long way to refuting allegations of undue influence or lack of testamentary capacity.
When making your own will it is important that the last will is easily identifiable. It is probably better to destroy all previous wills to avoid any confusion. If you are worried about any possibility of a challenge you could make copies of earlier wills and write `revoked' across the top.