This is going to seem pretty obvious to most people, but it wasn’t until recently that I realized that keeping the kids’ room dark helps them sleep better, which makes for better temperaments during the day.
When my boys were younger, they always wanted a night light on in their respective rooms, so I figured I’d just keep the blinds and curtains open overnight to help them sleep. As they’ve gotten older (now 11 and 6), the habit stuck. Then I realized one night recently while standing in my younger son’s room, which faces the street, that it was really bright outside from everyone’s house lights. I immediately shut the blinds and curtains, rendering it completely dark in his room, and have done so from then on.
Since then, I’ve noticed that his meltdowns at the end of the day are less frequent and they don’t last as long. Not sure if there’s a direct correlation, but it sure makes sense!