Avoid the rush – Give yourself ample time prior to your round to be on the tee box 10 minutes or so before your allotted time. As a rule of thumb, I would always be finished warming up and ready to walk over to the tee box as the group in front was leaving the teeing ground.
Order of play – Unless otherwise stated, be sure to allow the player with the lowest score on the prior hole to tee the ball off first and follow in the order of lowest to highest score until everyone has teed off. The person who is furthest from the hole thereafter will hit the next shot and so on. Often with a group of your friends this doesn’t apply but always be sure to check.