Suspension is the key.

 

Though I feel a properly set up suspension is a great asset to a quad...In my opinion, it's the rider that makes the bike look good.
No question about it...whoops on a quad are tuff..By nature of a locked rear axel..those bumps are gonna beat you up...You will notice that the riders that do good in the bumps are very agile..they are all over the quad...balancing and making adjustments as required to keep these 350 plus pound bikes in a strait line. You go crooked...and you can almost always bet on a world of hurts coming your way.

So like mentioned above...practice practice...and remember that you will rarely ever find two identical track conditions. Keep a steady throttle...good bend to the knees and elbows out to the side as best you can....never enter sitting...you will find yourself going faster each time you try them.