Your first concentrate should be on farming, cause a farmed fiora is too hard for every enemy. If you are high farmed and there are not too much armored champions in the enemy team you can take a second bloodthirster instead of the Youmuus Ghostblade. you also can try to counterjungle when you saw that your enemy was back or you killed him, you go to ther red buff if it is there you steal it, if not you go back to your lane and you can try to steal it when its up, if you completed your wriggles lantern it will work really fast.

with Fiora you dont need a teleport or something like that! even when you play vs 2 enemies at top, you'll rape them. Ghost: its a very good spell for fiora because, it can be useful in a chase, or when you are chased, and it can give you the necessary centemetres, which are needed to use a next 'Q' or your Ult. Ignite: everyone knows that Fiora is a good champion for tower diving, not at least because her ultimate 'Blade Waltz' but many solo top enemys got the summoner spell 'heal' and can rape you with it at there tower, so you take ignite and the heal is more useless than 'cleanse' vs Fiora :D

Many of you will think the item Tiamat is quite useless.... IT ISN'T. The ultimate attack 'Blade Waltz' doesnt ignore autohit-effects, and that's the part where Tiamat is the death for the enemies, you are dealing so much damage with your ultimate, and you change it into MORE AREA DAMAGE, that is perfect for lategame-teamfights.
When you are gettin dead often buy a frozen mallet in your build it will help you to get a little more tanky, and your auto-attacks and your ultimate will slow enemies

Mordekaiser: activated his 'Mace of Spades', cause it is a stronger auto-attack what means to you you can block it easily and he wont get any shield on his passive
Nasus: activated his 'Siphoning Strike' block it! it is only an auto-attack
Talon: most talons activate 'Noxian Dimplomacy' before they jump on you, you see talon running at you? 'RIPOSTE'
Shyvana: activated her 'twin bite' (same as Nasus and Mordekaiser
GANGPLANK: his 'PARRLEY' can be blocked by you too, when you have got a good internet-connection and a good timing, it should be easy to block it.
Vayne: after her 'Tumble' her next auto-attack will deal bonus damage, so block it!
Twisted Fate: when he activate his 'Pick a card' and you see he want to throw at you, 'RIPOSTE' you cant block the status-effects, but the bonus damage ;)
Poppy: when she activates her 'Devastating Blow' (same as Nasus)
Trundle: when he activates his 'Rapid Bite' (same as Nasus)
Udyr: when he activates his 'Tiger-stance' block the first hit he wants to give you!
Shaco: you saw him getting invisible? -'RIPOSTE'
Akali: when she threw her 'Mark of the Assasin' her next auto-attack will deal bonus damage, and when she does her ult she does an auto-attack immediately, so 'RIPOSTE'
Jax: when he activates his 'Empower' (same as nasus)
Shen: when there is no cooldown on his passive his swords are 'blinking' in red and blue, block the next attack!!!
Kennen: you see his churik is on thunder? he throws? 'RIPOSTE'
Wukong: when he activates his 'crushing Blow' block it, and when he isnt farming try to do 'Riposte' too cause he could be invisible and behind you :P
Blitzcrank: when he activates his 'Power Fist' he will deal doubled damage, BLOCK IT, when you are grabbed activate it too cause every b-crank does his 'Power Fist' after it
Lux: if she hitted you with an ablility, her next attack will make bonus damage, BLOCK IT!
Nidalee: when she is in form of a Puma and her mouth is 'blinking' her next hit will make tons of damage, so block it!
Yorick: when he activates his 'Omen of War' he will deal bonus damage at next attack and a ghool will appear, you can block the damage,but the ghool will appear.

A question is, when every auto-attack-effects aren't ignored, and i have lifesteal, when do I use it? For Teamfights:First look on your items, are you fed? if yes do it when your life gets under 40% if not try to do it at 50-60 or to steal a kill.
In Solo-top: you go in a 1vs.1 with an enemy? so do your ult not too early, do it when the enemy is under 40% health.