I'm pre-solo so take it for what it's worth. First, I get excited just being in the plane, and the adrenaline masks my fatigue, so I'll hit a peak in landing performance then decline. The trick is to recognize when you're tired by your performance, not how you feel.
I find that as I get tired, my comfortable round-out height gets higher (too high). What I try to do is get the sight picture just a little higher than it is when I'm on my takeoff roll.
Also, the more landings you have, the less behind the airplane you are. Once everything becomes close to automatic, and you're even with the plane, your landings will improve. Additionally, as you get more time in the round-out/flare the slower time will seem to move so you'll be able to keep up with the plane easier.
I've touted the runway expanding faster when you get to round-out height, but even though I've seen it happen in videos, I don't consciously see it, even when I look for it.