At 85, it is death strike all the way to 120. Depending on your template and how many skills you already have, but when I start a new char that I know I want ninjitsu, I'll put necro and spirit speak just enough to be able to go into lich form and cast a wisp (both for mana regen) and enough melee weap skill (arrows could get expensive if you tried on a archer, I like to go with Mace and use the boomstick because it also has MR on it) so that I have a good chance to hit (50+), put as much items on so that you are at the cap on LMC, MR, FC and FCR (resists on suit doesn't matter), equip the fastest weap you have for your melee skill and train away on a pet (doesn't need to be bonded just tamed and you must be unguilded and not in Fel), and since its a new char I let focus and med go to GM.
If this is a fully trained char, then pretty much work with what you have and wear items to get to the cap at LMC, MR, FC and FCR.