Hi, this is my first guide on moba.
This is just my way of playing Miss Fortune, there likely better out there but this have gotten me many won games with 3-1 kd+ games.

Pros
High damage
Wicked movespeed
Great harrasment
Easy to play
Hard to catch

Cons
Squishy Earlygame
Easy to catch once the passive is down
Gold Hungry

I like to take 21/0/9 for better leveling and increased damage
19/0/11 or 21/9/0 are also good options but i havent spent much time in said mastery trees.

Offensive 21 points max
Deadliness 3 for increased crit chance, since this build focuses hard on crits
Cripple/Archmages savvy 1 cripple for better exhaust, archmages for a filler in case you pick something else
Allacity 4 bonus Attack speed is allways lovely
Sorcery 4 the cdr will come in handy with your ult and q
Archaic Knowlegde 1 your W E and R deals magic damage
Sunder 3 Your auto attacks and your Q deals Attack Damage
Brute Force/offensive mastery 1 for bonus damage
Lethality 3 mini infinity edge
Havoc 1 more damage for our killing machine

Utility 9 points max
Good Hands 3
Spatial Accuracy/Perseverence 1 in case you take tele, otherwise the bonus regen is usefull
Awareness 4 for level superiority
Greed 1 for bonus gold, miss fortune is a massive gold sink.

Defense 9 points max
Ressistance 3, you will face alot harder magic damage harrasment
Hardiness 1 for a filler
Evasion 4 for a chance to keep the passive
nimbleness for the movement

I go for
Desolation on Quints and Marks for much needed Armor pen
replenishment on seals or glyphs for so very needed mp/5
and i on ocasion also take magic resist on glyphs

Flast:
its a must, you have no real escape sequence otherwise.

Options
Ignite:
great for fb and that damage boost.
Exhaust:
usefull if you lane with someone, otherwise go ignite.
CV:
maybe if youre a CV pro, otherwise leave it for the support.
Teleport:
great if you solo lane, otherwise leave it. you have a passive.
Heal:
if youre new to LOL.

I like To start of with a Dorans blade(sell when you need more space) for the early game stat boost, its too much too not love, an other alternative is boots with 3 healing potions for longer time before the first b or a brawlers glove in case you feel lucky. at the first b i like to buy lvl 1 boots, and if theres money for it an avarice blade for crit and gold(sell it after you finnish infinity edge).
At second b it should be late earlygame or midgame, now is the time to start building infinity edge and phantom dancer, however i also like to buy a giants belt before i finnish infinity edge for survivability.
next item is a warmogs armor(allways first) can be switched with frozen mallet, and a atmas impaler for armor, crit, and damage.
last item is completely optional, i usually get a last whisper or an mandreds bloodrazor, but again it depends on the enemy team.

dont be afraid to experiment with the items, any improvements are improvements.

Q on hit effects aply on first hit, use it to harras, nuke farm basicly evrything.
W constant stacking kassadin w without the mana regen, and the speed bonus is allways usefull, great harrasment tool and damage booster.
E mini Exhaust, magic dmg.
R great in lategame, otherwise farm minions with it.
Passive, let other initiate if you lane with someone, otherwise use it to dodge skillshots.

Farming
I CAN NOT STRESS HOW MUCH YOU NEED GOLD!
use your q and r earlygame to farm. make sure you have 35+ minions at 5 mins
take wraith if you dont have a jungler.

Well it might not look as pretty as other guides, but i hope you got something usefull from it.
sorry for the bad eng.