Neither of these will give you much of an advantage, but they are advantages.

In Arathi, when it says 30 seconds until game begins, start running into the gate. Right when it says the game is beginning, there will be a short second where you stilll can't run past the gate, BUT, you can JUMP over it. On a normal mount this is about a 15 foot head start, on an epic more along a 30 foot.

Also, whenever you get a movement speed boost thats timed, when it reachs 0 seconds, waith .5 seconds and then jump. The buff will end mid flight but you will retain your speed until you hit the ground.

If you do this from a hill you could easily end up with another second or two of the speed buff.