Keep me logged in until I sign out. Many states provide suggested forms, and in some cases, required language for advance directives.
Most states have specific witnessing or notary requirements.
Follow these requirements closely. The most important point to remember about forms is that they are supposed to aid, and not take the place of discussion and dialog. Therefore, a form ought to be a starting point, not an end point, for making your wishes known. There is no ideal form. Any form you use should be personalized to reflect your values and preferences.