Among the advice given by the columnist is a recommendation to write one's reasoning for unequal estate shares in a will. Similarly, one could write a letter of intent.
Experience in a litigation setting shows that such clauses and documents rarely carry much weight in court. The reason is that they are typically drafted by the law office preparing the will. If the testator lacked the capacity to make a will, the court will often think, then yet another piece of paper the lawyer drew up does little to add to that capacity.
Practical experience shows that the single best way to leave unequal shares in your will is to tell your children (or other heirs) you're doing it and why. Nothing leads to estate fights quicker than surprises in a will. Similarly, a child that has had months or years to digest the fact that he is receiveing a lesser share (and who has heard "why" straight from the testator) is much less likely to file a suit.
Second to this is some recording or document that demonstrates capacity. A handwritten note or letter; a video tape; a recording of the conversation with the lawyer; or (in extreme circumstances) examination by a physician competent to evaluate mental health are all ways to head off an estate fight before it begins.