If you are facing stealthers anywhere on the opposing team, or bursters in middle, try start with a Doran's Sword.
Then go Dorans Sword #2, and then Dorans Sword #3, then Mercury boots and continue on. A full set of yellow hp@18 runes helps as well. An Aegis after boots isn't too bad either, someone on your team will need one. It still leaves you with an open slot for that 4k gold IE.
A whole set of blue mana regen@18 runes helps with kiting with multishot spammage.
When you hit 6 immediately ult Annie to hurt her and then run behind your tower and recall to buy new items.
Annie will be low enough she will have to go buy as well. When you both come back you will have more then enough hp to live through a fuzzy wuzzy ol bear.
no im sorry they're a waste of time money and inv slots play passive snipe creeps and you dont need any of that horse**** (P.S. I see anyone with a doran's sword and i smile cause its a free win)