Geez, you guys over do things!
A good strong coffee before hand to settle the nerves a bit. I just pitch up at the tee box 10 minutes before hand, pull the club, take a few practice swings and fire away...
Really, even on tour I never hit balls before the round. If I was forced to be at the range before hand (yep, some tours insist on it) then I'd hit 10 wedges, 10 7-irons and a driver or 2 over about 30 minutes and then head to the tee.
Stretching and stuff - never done any of that before the round either.
Bad I know but it works for me.