Max q first, then e. Take one point in w at level two. Only counterpick with kassadin, as someone like talon with stomp on him. Poke with q as often as possible, and at 6 you can 50-0 most ap mids. I like to rush a rod of ages, then lichbane on him, getting merc treds whenever convenient. Post 6, roam to bot lane, assassinate their carry, and go back to lane.
Your normal combo should be R-Q-E-W-auto attack-R-ignite.