Miss Fortune is in a kinda awkward spot at the moment, but getting her to work is a piece of art - and it is recommended to Duo Queue when playing her.

She was highly popular in the start of the season due to her high harassment in laning phase with her E - Make it Rain combined with Comet.
The first thing about her, you do NOT want to make extended trades with your enemies. 1 Tap and out.

This build makes is focused on making her a viable ADC rather than an AD Mage!
We have to make her a TANK BUSTER because she still lacks hardcore Hyper carry abilities and her DPS falls of after her initial attack with her Passive:LOVE TAP!

PRECISION
Conqueror is perfect for taking down tanks, with 20% true damage on her abilities and auto attacks in teamfights!
With her lack of hyper carry abilities, you will have to play defensively on her, because you are not going to win extendend trades with her against Caitlyn, Tristana, Kaisa or Varus for that matter.

But she's got a game winning ultimate: Bullet TIME!
And this is why we are using fighting runes, to make up for all her flaws.

Bloodline for better lane sustain and trading, because you are not geting away from lane without having to trade a few times. This makes it easier.

Cut Down is for Tank busting in this current meta.

Secondary - SORCERY

We want that extra movement speed from CELERITY that synergizes well with her Passive movement speed from STRUT.
With Boots of Swiftness, Max level in STRUT and CELERITY you will get 478 Movement Speed and that is with the Soft Cap on movement speed included in the calculations. This gives 12+ AD extra and 11 MS as bonus from Celerity.

Gathering Storm is used since the average duration of games is around 25+ min in Diamond and higher. Beyond the 30 minute mark it beats every single rune in efficiency in pure stats.

You play Miss Fortune to abuse her early laning presence and dodging prolonged trades, and get to mid game without dying and just farming up. Because you will later on in teamfights be a WALKING ULTIMATE that will be able to take down tanks early on.

This GUIDE is not for snowballing in laning phase, this is for winning fights and games!

Ghostblade is fixing all her early game problems with making trades versus the enemy carry, and gives some nice armor penetration.

But after that, its all about getting Essence Reaver and Infinity Edge, to increase the damage output on your Ultimate.
Black Cleaver/Lord Dominik will be bought as the 4th item, depending on what you are facing.
2 full tank builds on enemy team = Lord Dominiks | Otherwise its Black Cleaver, since it helps out your team with lowereing enemy armor.

As said earlier, Miss Fortune is a champion that oftens needs a Duo Queue Partner, since she is vulnerable in laning phase if facing hard engagers.

Alistair, Thresh and Leona are something to look out for.
And what you want is to poke your lane opponents down, and not having to trade auto attacks with them.

This can be done with support like Lulu, Karma, Zyra - and its very important to recognize who to focus in lane. If they got a Tahm Kench, and you cant get to their AD Carry in lane, then just wear Tahm Kench down until he is out of HP potions.

And then suddenly their AD Carry has to step out of the comfort zone themselves to be able to lasthit against you, and thats how you break down their lane.

Talk with your lane partner and try to synergize your aggression on the same target, at the same time. IF enemy support tries to poke/trade, then both trade back. Its simple, but it makes a huge difference, since they have lost more health than what they took.
Mentality-wise keeps most supports from making those exchanges again, since they knew they lost that trade last time.

Keep your distance to your enemies as Miss Fortune. And look out for openings to activate Strut for Disengaging, since minion attacks removes the Movement speed buff.

Attack the ranged minions and keep them at low health and then back to focusing the melee minions in lane. This give you an opportunity to use Q when they get close to minions.
As said earlier, you dont want to get close to them, just 1 Attack and then out again.

Miss Fortune is a walking Ultimate and that is how we play her.
Stick with your team, and stay in the backline. Dont give your enemies a free pass to get a hard engage on you.

If they get baited into a fight, you will easily dish out 3-5K damage in teamfights in the mid game due to your insanely strong ultimate.

Normally Beserkers Greaves would have been the other choice, but for most players who is rather new to Miss Fortune, it is all about positioning. Boots of Swiftness makes it so much easier to get the right position to land that sweet PERECT ULTIMATE that wins the game.

She shines in teamfights, not in 2 versus 2 skirmishes mid game, since her sustained damage falls heavily off after the first 2 seconds of the fight. REMEMBER THIS!
Farm, dodge all small skirmishes and wait until your game breaking Ultimate can be used in that 5v5 fight.