Contrary to popular belief, at least in Alberta, there aren’t a lot of formal requirements for a will to be legally valid.
A holographic will is a will that is done entirely in a person’s own handwriting. If a will is holographic (entirely handwritten), then it doesn’t even have to be witnessed. I would always recommend dating a will, as the most current will typically overrides older wills.
Non-holographic wills, in other words, wills that aren’t handwritten, should be witnessed by two adults who have no interest in the will. In other words, the adult witnesses shouldn’t be beneficiaries, executors, guardians, etc., and I’d also recommend that spouses of those people be excluded as witnesses.
What to include
Technically, you don’t even need to specify an executor in your will, but I always recommend indicating a first choice for executor and at least one alternate. The will should indicate where at least some of your property will go after you have died.
Capacity and voluntariness
A testator, that is, a person doing a will, should have a minimum level of mental competence when doing a will. A court may have to decide after a person has died whether this requirement has been met.
A will must also be voluntary. In other words, if a family member or some other person is exerting too much pressure on the testator to do a will, or to do a particular will, it may later be found to be invalid.