This build is almost like Miss Fortunate Killzone build but with some changes to make the ultimate Miss Fortune to dominate in LoL. What I changed are the skill sequences and the items. For the skill sequences I made it so you can farm a lot in early game.

PROS.

Ranged
Massive damage
Strut
AOE attacks
Amazing in team fights
Carries team

CONS

Squishy
Need team to be helpful
She is useless when ganked
Strut disappears when hit

ITEMS AND TECHNIQUE

The items are the biggest change to the base line of my build, Miss Fortunate Killzone. To use my build you must be some what familiar with Miss Fortune because I made it so you get The Bloodthirster first, making early game some what of a challenge to survive, play smart.

When you first start get your Boots of Speed and your health and mana potion. Your Boots of Speed are required for your first item and your health and mana potion are for survival. Solo mid because Miss Fortune will need the extra levels. Last as long as possible in your lane to get the maximum amount of level and gold. You will find that Miss Fortune will be always low on mana in the beginning so use your skills when you really need to, use Double up's range to your advantage. Don't use Make It Rain or any skill too often, save your mana. Go back if you are low on health or when you have enough gold to get your Berserker Boots and your BF Sword. Once your level 12 other players should be lower level so change lanes and help out your teammates. Then just follow the Item Sequence through out the game. You will not be as squishy after you get you Frozen Mallet.

CORE ITEMS

For the last item it is really up to you depending on your situation. In my case I like to have more damage. Possible options for the last item: Last Whisper, Madreds, phantom dancer, etc.

TIPS:

Don't get greedy. Don't chase your enemy if they are pass the turret since you are squishy the turret will possibly kill you. Do not run around looking for your enemy stay with your teammate if you are going to look for them because Miss Fortune is not great when against a gank. When playing Miss Fortune be *****, you want Miss Fortune mia after you have destroyed the mid turret because you don't want the enemy team to target you. With Miss Fortune you need to hit and run. Stay behind your teammates when you are in a battle don't be in the front. Be aware of the map, if there is a battle going on somewhere and someone is escaping come on the other side and chase them. Miss Fortune is able to change lanes very easily and help teammates when in need.

EARLY GAME
In early game start with some boots and one of each potions. Farm as long as possible, consistently harass the enemy and stay out of their range. When they are harassed enough go in for the kill. Farm until you have enough money to get a bloodthirster and beserker boots. Try to get the bloodthirster as fast as possible so you can stack damage on it. Be aware of any ganks if you are dominating the mid lane. When you have destroyed the mid tower, DO NOT STAY THERE! They are obviously going to gank you there.

MID GAME
So you have destroyed the tower now go get some buffs and switch lanes to help gank. When ganking tell your teammates to engage first then you pop out of nowhere and kill them. After kill either the top or bottom help them destroy the tower then go to the remaining lane and help them destroy their tower. After you have weakened their defense push one of the lanes. By this time you should have your beserker boots, a bloodthrister, and a frozen mallet. After the frozen mallet you should have a lot of health.

LATE GAME
By late game the enemies defenses should be so poor that they are forced to defend making them unable to farm. The game should be almost ended. If it seems to still be continuing you should have gotten your phantom dancer. With this your team should be able to Baron no problem. And once you have Baron finish the game. Note: Best time to Baron in late game is when they are occupied with super minions.

This is pretty much the build I came up with for the Ultimate Miss Fortune. With this build you should be doing around 800 Crit and Crit chance will be increased after you get your phantom dancer. Hope you like my build and post your best score up if you decide to use it. This is my first build so its not that pretty but its the content that counts right? I will refine it a bit, don't worry.

UPDATES

-I did a switch, so now you get the bloodthirster first so you can stack the damage early.
-Changed the last item.