Miss Fortune is my favorite character. I've been playing her since the first week I played the game. She was the first character I ever had fun with. Naturally this means that I've been screwing around with a bunch of different builds and item combos to figure out what the best setup is. This is what I've found I love the best. I just played a game goind 16/1 (sorry I can't put up a screenshot but if you dont believe me honestly IDGAF) and I was just thinking to myself that this was the best setup I've used so far.

Pros:
-Sexy Chick
-Amazing Skins
-INSANE DAMAGE...like....crazy

Cons:
-I had a twitch I was laning with complain I was killstealing while I was doing all the damage...expect noobs to QQ.

Armor Penetration is key for pretty much any AD toon. It will increase the damage you do to everyone as well as those pesky high armor tanks. So the quintessences and marks are straight up armor pen. I take damage on the seals and the glyphs because I want to nuke people down. I've seen MF builds take mana regen before and it honestly seems pointless to me cause her mana is fine and I want the damage.

Nothing particularly surprising here. You want all the attack speed, crit, damage, and armor pen to nuke people down. Screw the standard 21/0/9 setup. I don't see why you would give up good slots in the damage category just so you can have a small amount more mana regen. 24/0/6 all the way.

You may think that you need more attack speed to start with but the damage is more important. Impure shots can handle the attack speed for us while we work on our damage. Doran's blade comes first because it will give us some good boosts at the beginning. You want to rush straight into the B.F. Sword so you can start bumping up the damage right off the start. That will build into an infinity edge pretty quick because it is an excellent damage item and gives decent crit. At this point take the last whisperer because again, armor pen is amazing! Next take up a vampric scepter for some more lifesteal. At this point its okay to start building some attack speed but I wouldn't go for anything higher than a zeal. You could even wait until later on for the zeal but its kinda nice to have at this point. The bloodthirster is a great item for MF because as shes knocking out her auto attacks shes also healing back up to full so the bloodthirster is a must have next. Finish off with a frozen mallet for some health as well as the damage and nice slowing effect and the phantom dancer for the attack speed and oh so wonderful crit.

Double up does insane damage. This is a must for maxing first. Next up we want impure shots because of the attack speed. This attack speed comes in handy especially while we are still waiting to get our zeal/phantom dancer. Make it rain is maxed third because other than some earlier game harass and some slowing this is MF's least important move.

Exhaust and ghost are the best spells for AD carries in my opinion. Exhaust keeps the enemy from getting away and ghost allows you to keep up with them just in case they do get away. Between the two you should be able to pound out all your auto attacks even on targets that are running like hell (trust me they will with this build).

Make sure you dont waste your ulti. If you use it at a weird angle in the team fight it will be really easy for people to get out of it. Wait for the perfect moment. Dont get an itchy trigger finger. Dont worry i understand the need to fire of the delicious volley of bullets while hearing the sexy laugh. One thing i didn't realize for a while, double up does MORE damage to the SECOND person it hits. Keep that in mind for your harass. Make it rain honestly does not do as much damage as everyone thinks it does. Harass with it some at the beginning of the game but dont waste all your mana on it. One thing i love using make it rain to do is get the pesky bush humpers out of the damn bush!

Rushing the B.F. sword can be a bit tedious if you're not last hitting. Wait until the minions are at about one hit's worth of damage and then fire your bullet. The more last hitting you do the faster you get your sword.