Miss Fortune Build
Not Updated For Current Season
I start with Boots of swiftness for easy kill when Summoners run away she can easily run for them.
I have this build because because i find is very powerful with her critical. Build that up with Infinity edge with its 80 attack and 25% critical chance and 250% Critical,also Phantom Dancer it seems to just fit with a critical build, and Miss fortune is all about the attack with her.
Usually go with Premallet now for the Health if i'm not fed (in case i'm facing Tanks or some one with more range) when i'm not fed but I go with black cleaver it increase her attack speed with 50 attack and its armor penetration its good for mid game ganks.Then i finish off with Frozen mallet freezing and slowing them down really helps it kill them before they get away.
Lastly Hextex Gunblade Start off with the books then the Septor, and finish off with Hextex Revolver before getting getting the Gunblade Gunblade is mostly for her Ability power attacks because I don't have anything for Ability Power the only thing i find it useful for is her ulti. I only use Make it ran for slowing down Summoners and to farm minions
Most people will go for Blood thruster but these items are better.
For Runes I Use full Greater Mark of Desolation and Greater Quintessence of Desolation, Armor Penetration is a must for Miss fortune.
And I use Full Greater Seal of Alacrity and Greater Glyph of Alacrity for Attack speed. Attack Speed is also a must. The more attack speed the more hits you can get off for the runners.
For masteries i mostly go with 27/?/? depending on what my spells are. Example I put one on Ignite if its equipped. I go like this because I like to put attack on miss fortune.
Deadliness: I Fill up points in. This is to help with the critical chance.
Archmage's Sawy: I fill up to help with the Ability Power because I don't have much for the build.
Alacrity: I fill to get plus 4% of attack rate.
Sorcery: I fill to help out my penetration power.
Archaic Knowledge: I fill this will help your make it rain do a bit more damage.
Sunder: I fill up because who doesn't like Critical Strike.
Offensive Masteries: I fill for Farming the crazy minions.
Brute Force: I fill up Because is fun to have attack power. makes miss fortune big and strong.
Lethality: Critical Strike is the best thing ever for a carry and Lethality is a huge improvement for Critical strike.
Havoc: I fill up to help the one hit half there hit points double shot.
The rest of the masteries is up to you. You can go for Armor or Regeneration Hit Points and Mana. Also ajuest your masteries to match your spells like Ignite or ghost.
For spells I tend to go for Ghost and Ignite.
Ghost is good for running into battle or even away, and with boots of swiftness its like no one can touch you. Also its also good for my kill the runaways plan.
Ignite Good for early game and for the runaways if you can get a champion up top of a lane and you have a Champion running away Ignite can weaken them to a point some one up lane can turn and 1 hit kill or when you keep up with him and hit him with a Double shot for a easy kill. (note: you got to do this when there hp is very low so fight till you can get his hp low.), also ignite is good for getting Kill Steals lol.
Well that's what I go for anyways you can replace them with Clarity,Exhaust, or Flash in stead of Ghost.