I'm thinking of using small tokens to remember in-game effects that I often forget (due to having multiple armies and little time to play).
Things like +1 to hit, to wound, reroll 1s to hit, to wound, etc... Small tokens that can be placed on the side of a unit to remember which aura effect or similar buff/debuff affects them.
In my last game I used the Tau Kauyon ability in my first turn (reroll every failed hit roll for affected units) but I actually forgot that I had it and I only rerolled 1s due to Markerlights
It sounds stupid (and it is) but playing a full game on a weekday night is definitely tiresome.
I'll probably print some very small cardboard tokens for now and see how it goes.