1) Don't be afraid to play/dep/jam with someone when they ask - you don't have to be flash, or even that good..... Most people just want you to be dependable, turn up when you say you'll tun up and cover the basics.
2) Start playing double bass as soon as you can.
3) When that bell end of a a guitarist accuses you of stealing band money, kick him very, very hard in the happy sack, cos you'll regret not doing it when he quits the band ten days before the U.S. tour.