If you did any research about Fiora, or saw it in game, you'll see how it owns in pvp. It is indeed a very useful and strong pvp hero, and pretty hot too. In this guide, I am trying to share my way of controlling her efficently, and you may want to check it to get ideas. If not, you can always check other cool known guides and stuff :)

If the gamne is not over / you have more money left, i would suggest you an item with armour, for example Guardian Angel(2600), or such, since this build doesnt have a large armour bonus. Or, Wriggle's lantern, which is cheaper (1600), and also gives attack damage and life steal.

You may want to start any skill you want. First skill will be useful against heroes, and secon skill will be very good early levels, considering it have a passive attack boost. As for the third skill, it is good for both slaying minions or pursuing champions with low health. Or in case of emergency you may use it to run away from enemies, since it boosts movement speed. Ultimate skill is one of the best anti-champion skills in game, dealing a lot of damage in 1v1 and I would reccomend it after using first skill, so that you will get close to your enemy with wider ranged fiest skill, and then hit the enemy with ulti, slowing him down I'd you have mallet, and then pursuing them with combination of 3rd or 1st skills, depending on how much HP the target has, that is if the target is alive.

This is my second fiora guide, nothing much changed but items. I would suggest you to make up your own item combination, which suits you best. In this setup, fiora is a bit tanky, because of +700ish health, but also as quick as an assasin, both attack-wise and movement-wise. Combined with skills and freeze effect of the mallet, you'll be inavoidable during combats, especially 1v1. Along with the third skill "e", your enemies wont be able to see your sword nor your feet dancing on the ground :)

In this set up i choose ignite and exaust. Let me explain why i did so. First, you NEED exaust, it's extremely useful, especially before you get yourself a fancy mallet, this skill will prevent anybody from escaping, turning them into pieces of cake. If timed right, the kill is yours to collect.
And again in early game, you may need a little attack support, and ignite is for that! And even in late game, if you do 1v2, and a healer is against you, you may turn the other f**ker into ashes, preventing him to get undesired healing effects!

YET; you may want to swap ignite with either Flash, or Heal.
Flash will be handy, suprising other champions and slicing em up like cheese, or you may use it just like exhaust, if the opponent is faster than you. Which in this case, it's not that likely.
Or you may use heal, because in early game fiora is a little weak, or rather fragile, you may need some healing assist. And healers are never there when you need them, especially in early game.

Fiora needs an early level training, or else it'll get harder for you to level up. As soon as game starts, try to level up. Around lv11+ you'll be starting to pwn people in pvp. Until you are lv11 you may want to team up with a ranged champion in order to put pressure on enemies in early game and level up quickly.

PROS

Very strong in PvP
High attack and attack speed.
Can be used as a Tank, if used correctly.
She's hot.
Aigle and can deal a lots of damage to multiple enemies with a good support.
Dashes give Fiora long distance attacks, and can take out ranged champions if used correctly

CONS

Low health. This may cause inexperienced users to go down pretty quickly.
Needs support early game. ONLY early game.
The cape may cover dat *** time to time :(