Play her top with a heavy armor rune page (Usually I run flat armor quint and yellows, magic pen reds, scaling mr blues) and a mastery tree with thunderlord keystone (12/18/0).
You go into lane and get

and for the last 2 items grab one of the followign depending on what you need
by checking your tab and see what you should itemize for.
That will allow you to duel pretty much any bruiser (that is AD) by trading correctly.(R,aa(shen), W, Q, AA (shen)) landing a Q before hand can let you do a full in but most people will be wary of the Q first (they wont expect the r in first). You still have enough damage to solo carries on decent time as long as you don't fall behind early. For AP enemies you could run an MR run set up but it doesn't work quite as well since Diana base resistances are better suited to counter AD. For teamfights, ideally you want to land a Q on a squishy and then use your combo followed by an immediate stoneplate but if your team is close you could R, W, AA (shen), into stoneplate (E if necessary) , the burst is almost immediately and will burst any squishy for at least 2/3 of their HP, you use the time on your stoneplate to wait for your Q to finish the kill and to dissipate all the focus you will get. Usually teh carries end up zoned, killed or forced to flash away.