Draft as many packs and cards as you think makes sense. I wouldn't give card pools of more than 10-15 though.
Make decks of 5 cards.
You get no free basics, you must draft lands.
Start each game with all 5 cards in your hand.
Reveal your hand at the start of the game.
You don't lose from drawing on an empty deck.
If you would shuffle your library, your opponent chooses the order. (There's exactly one card that does this.)
Play a match of two games against each other player, once going first, once second.
If the game state is exactly the same 3 turns in a row, life total can optionally be used as a tiebreaker, or the game ends in a draw.
Wins give 3 points to the winner, draws give 1-1.
So the valid match results should be 6-0, 3-3, 0-6, 4-1, 1-4, 2-2.
Add up all the points you got, highest total wins the draft.