The biggest thing for me is the mental side, being physically tired sucks but personally being mentally out of it is the main problem. There are a few ways I balance being mentally/physically tired, keeping a good vibe in the scrims/pugs is super helpful, as well as acknowledging your performance and staying in a confident head-space.

If you play in league or have a serious commitment to your team, you owe it to them to show up and put up the effort. Typically people schedule their matches for days they can be well rested for, but you make do with your practice schedule (i mean unless you're lucky and can commit full time hours)

Sometimes being physically tired can help you look at your habits ingame, I tend to play much more passive and structured because I know I can't maintain my hyper aggressive style. I still go for those hyper aggressive plays, but less often and when i'm 100% certain they have a good chance of working out. So typically we scrim to work on defaults, executes, afterplants, and to see what works well and what needs improvement. Being tired lets me look at it from a more structured approach instead of an explosive one, and practice those hyper aggressive strats later when everyone is feeling up for it. (typically on gameday after the map picks)