I've also began ranking up the secondary skill as opposed to rushing 1 skill, that way my whole arsenal will be consistent and threatening as I level up. I still leave the defensive skills on level on though.
My masteries are 9/21/0
Taking points in Relentless, Tenacity, and having on point in that one "legendary armor mastery"
Spells are ghost and ignite
runes are armor pen red, armor seals, attack speed quints and magic resist per level blues.
I go cloth 5 pots and try to farm up for a boots of swiftness. By the time my core build is done, I'm almost as immune to slows as master yi while in highlander. :D