These are just suggestions.
- Make sure the list is written in such a way that you'll feel OK reading it when tired: avoid including tasks you won't want to think about when tired; phrase them so that they sound polite, not "Do this!" but whatever gives you the feel of "You might like to do this." or whatever makes you feel good. Also phrasing efficiently, not too many words. (These are mostly contradictory requirements.) Whatever combination works best for you.
- Think about where you're likely to be when tired, e.g. sitting in your office chair, walking into or out of your office etc. Write them in biggish letters and post them on the wall so that you can easily see them by just turning your head slightly.
- Practice looking at them regularly. E.g. develop a habit that once a day you'll look at that list, or once a day you'll do at least one thing on that list, whether you're tired or not.
- Identify the time of day you tend to get tired, and develop a habit of using that list at that time of day, whether tired or not.
- When you do something on that list, give yourself a reward.
- Include rewarding activities on the list, or things you're likely to enjoy doing when tired, e.g. go for a walk, have something to eat
- Develop a habit that several times a day, you evaluate your energy level and think about what kinds of activities are most suited to your priorities and energy level
Inability is an abstract thing involving comparison with alternate universes; it cannot be experienced.