Always at the beginning for me. Like Zeus said, I'm always worried I may have to leave before when I planned, or that I may forget about it.
Plus I have had a few really lucky casino trips where I have won big on as little as $10 in freeplay and never had to touch my bankroll.
Point play I'll always do at the very end, since I usually want to use it up unless its one of my locals where I'll keep a lot of points banked for future use.