Deciding what you won’t do makes every other decision faster.

Most decision fatigue comes from reopening the same question repeatedly. A standing no removes a whole category from consideration, so the choice is already made before the moment arrives and does not have to be argued again while you are tired. It also removes the negotiation, which is the part that usually loses.

Write down two or three things you simply do not do, in plain words, and keep the list short enough to remember. Say them out loud once to somebody. A rule you have stated is much harder to quietly bend.