Fiora's preferred lane is a solo lane for the exact reason listed- unless she's ignored by her jungle and is paired against someone with stronger sustain (Irelia, Udyr, and so on) she has fairly strong control of her lane.
If you
had to pair her with someone, you'd want them to be oriented toward effective crowd control (IE: someone like Leona or Janna who have a high cast rate of CC rather than Sona who's got a comparatively low rate) without overly compromising DPS. The only major draw back to Fiora in-lane aside from a relatively anemic survivability profile is that she's.....slow. Even with her two soft flashes and an MS steroid she can have a hard time keeping pace.
Almost any DPS Item is good her. Just make sure you don't focus too much on Attack Speed but more on Attack Damage (because you have an incredible attack speed boost and very high AD scalings on your abilities).
When using your
Lunge to harass, always AA after each use.
Lunge -> AA -> Wait ~ 0.5 seconds ->
Lunge -> AA -> Fall back and use
Riposte if you see the enemy turn around to AA you. The 0.5 seconds is to let your autoattack timer refresh. If you use
Lunge again too quickly, you will not be able to AA after it and you will uselessly stand still.
Use your
Blade Waltz to chase if you already used your
Lunge and
Burst of Speed. It lasts long (so your cooldowns are usually almost over after the spell), it follows your enemy AND makes you spawn right next to your enemy when it's over, making you able to land an extra autoattack again.
In general, try keeping your
Blade Waltz for as long as you can. You can use it when you are low on HP to make yourself untargetable and to gain back HP if you have lifesteal. You can also use it right before an enemy throws a spell at you to dodge it.
If you can make sure your enemy will die by using your
Blade Waltz on him, use
Burst of Speed right before ulting because when your ult will be over, your
Burst of Speed's cooldown will be refreshed AND you will profit of all the bonus movement speed it gives (can be useful to run away from tower shots).
Towers can't attack you while you are using
Blade Waltz so you have strong diving potential (know how much damage you do though... you could get yourself in trouble).
My opinion on some items for
Fiora:
The Black Cleaver is over rated on her while
Last Whisper and
Youmuu's Ghostblade are both underrated but that's me.