You ever played Le Blanc and made someones health bar disappear, but then you find your self completely useless because you have every thing on cool down? Well Fiora does that without the side effect of not being able to do any thing afterwards...

Best lane for Fiora is bottom. With either someone who can poke them down enough to where you can farm freely ( Orianna), and if they stick around get an easy kill, or with a stun heavy support ( Leona). These will usually end up either netting you a bunch of kills or assists either way you get gold and start the snowballing.

Not really going to explain too much but I'll explain a little. So Fiora gets so much attack speed (Roughly 2.3, .2 from the hard cap of 2.5) from Runes, Boots, Black Cleaver, and her E that you don't need any more attack speed then that. Phatom Dancer is pointless it will push you way over the Hard Capped 2.5 AS. If you go past it your wasting an item space for an item you can't fully use. So you stack damage items to put that near maxed AS to good use. Also this makes your Ult if used on a single target an insane nuke.