On my main guy I get on him roughly 20 minutes before I run. I start out with a few laps of walking, trotting and long trotting. Then go lope circles, a few counter arcs then back into the circles, trot some counter arcs, figure eights, walk a few circles then I tighten my cince and put my bands on then head to the arena during the drag and wait for my run.
He isn't a hot horse....but when he is at a race he KNOWS what he is there for and has a cocky attitude so he gets pumped and wants to go do his job. So I don't get on him to early or else we both get over anticipated and he starts getting a little hotter and impatient waiting and waiting. And 20 minutes is just the right time he is nice and warmed up, focused on his job, and goes and makes a nice run.