If your game takes long enough for you to finish your build with a Guardian's Angel, sell your Doran's Blade to make room for it. If you arn't getting focused or dieing alot in teamfights, skip the GA and get some more damage like a Madred's Bloodrazor.

If you are laning with an attack speed reliant champion like Kog'Maw, Warwick, etc. or anyone that would benefit from attack speed, max your E first so they get the passive. If you are soloing or laning with someone who doesn't need attack speed, I would suggest maxing your Q first for the extra damage.

Try your best to last hit minion while lanig like you would with any other characters, but once you hit 6, if theres someone who is 2/3 hp or lower, go gank them with your ultimate. You can also gank someone at full hp but make sure you can take them down so you dont waste your ultimate, and check beforehand to see if they have flash, if so and it's off cooldown then there isn't much of a point to gank them unless you have a silence or if you want to waste their flash.