Alright to begin - I think we all know how to get out of Arathi Basin before the game starts; if you don't here are the links for Alliance and Horde.
I'll make this short and sweet, so wont post any pictures though I think this is pretty self explanatory.
What I've found is that if you own a multi-passenger mount (ie. the chopper or travellers tundra mammoth etc), once you are outside, mount next to the gate and anybody still inside will be able to jump into your mount through the gate.
Also please don't reply with "This is common sense lolol ur retard." for obvious reasons.
Hope someone finds this useful/fun!