Fiora Runes explained
There's one set of runes for Fiora on patch
11.15
that is the clear favorite for LoL players and pros alike. The best Fiora Runes on the position 
Top are Precision as the primary path and
Inspiration as the secondary path with a pick rate of 49%. Besides runes you should take a look on Fiora Build and if you are interested in pro matches take a look at Fiora Probuilds. If you want to discuss
Fiora then you should visit the champion subreddit.
Primary path on Fiora
Precision improves attack and sustained damage on Fiora troughout the match. Most of high elo players – and our LoL pros in the the major regions – have agreed that
Conqueror is the best keystone rune to run on
Fiora. This keystone rune provides additional power in the later stages of a game. As soon as
Conqueror is fully charged, Fiora deals additional damage and gains life steal. This is usually followed up by taking
Presence of Mind,
Legend: Alacrity and
Last Stand.
Presence of Mind helps Fiora with the mana problems by restoring missing mana, if a champion is killed.
Legend: Alacrity grants additional attack speed to Fiora. With
Last Stand you deal more damage while you are at low health.
Secondary path on Fiora
When it comes to your secondary path, most
Fiora players prefer to go with
Inspiration.
Inspiration opens creative opportunities on Fiora troughout the match. On the
Inspiration path, the best runes for Fiora are
Magical Footwear and
Cosmic Insight.
Magical Footwear allows players to focus on those essential core items without the need to spend the additional 300 gold on boots.
Cosmic Insight grants summoner spell and item haste.