Beneficiaries (and any other persons specifically named in a Last Will and Testament) SHOULD NOT act as the witnesses to the maker’s signature on that Will, to eliminate any possible conflicts of interest.
It is a far better strategy to find persons who have no interest in the assets or distribution of an estate to witness the signature of a Will, so that no claims can be made against the Will after the maker’s death.
To easily and inexpensively prepare a Will document without the expense of an attorney, see Standard Legal’s Last Will and Testament legal forms software page.