For top:
Start with dorans blade for most matchups and corrupting for ranged champions or really tanky champions on who you are going to use a lot of mana.
First back get sheen, or corrupting(if you don't have) boots or another dorans. Finish trinity, boots depending on the team, also go spirit or deadmans depending on what you need in lane. Finish those two and go ga. For last item you can go black cleaver for armor pen or death dance.
For masteries I go 18/0/12. Get warlords blood lust. It goes great with your q and Trinity.
In lane stack your q graves pre 2 and wait for 4 of then before sending them. First e the enemy, if you miss don't summon, and then summon ghouls. Post 3 start with e q summon and w trap. If you can't do it fast enough do e w trap then summon.