I like the tip packlet they give you, definately a good starting point. In It was
Include some creatures at every cost from 2 to 6. This will make it more likely that you have a creature to cast every turn.
Try not to play 3 or 4 creatures of a given cost.
Don't play play more than 1 or 2 creatures that cost 1 mana.
Try to include as many creatures as possible with evasion abilities like flying, trample, and menace.
Look for noncreature spells that destroy your opponent's creatures, make your own creature larger,
deal damage to
creatures or player, or some combination of these.