Miss Fortune is strong in lane because of her Q and her W. However Miss Fortune can fall off late if not played correctly. You want to get kills and farm early so that you can carry in the late game. Miss Fortune's Q gives her a longer range to poke people with and her W gives her a good mix of Magic and Physical damage. This can make her harder to build tank against, however you do have to hit people multiple times for the magic damage to build up, this means that when you attack someone who is a tank it will be more effective and increase your damage significantly on them for a while.

Miss Fortune does require quite a bit of skill and finesse to play, so you will need to practice on her. This guide is not definitely what you should do, as the name suggests this is only a guide. It will guide you into finding your own way to play Miss Fortune that works for you.

Double Up (Q) - Double up allows Miss Fortune to poke her lane opponents or clear waves quickly. Using Double up to kill a minion causes it to do more damage to what it Doubles up into, use this to your advantage in fights and shoot minions a few times to allow double up to kill them and do extra damage to the champion behind them. If you learn the Q's range then fighting should become significantly easier.

Impure Shots (W) - Impure Shots can be used both defensively and offensively. When escaping fights you can use it to instantly give you max stacks of strut for a quick escape or you can use it for bonus attack speed when going in on someone. I would personally save Impure Shots until later in the fight when you can acuraetly judge whether you can kill the person or you need to escape.

Make It Rain (E) - Make It Rain's damage is almost negligible, use it to slow enemies that are escaping/chasing you. you can use it in fights for a little extra damage, however I wouldn't rely on it helping too much. If fighting yasuo it's a good way to remove his shield before going in.

Bullet Time (R) - Bullet Time is good for catching people that are escaping on low health after you've fought them. Bullet Time does more damage for every stack of Impure Shots you have on someone, However it does really low damage if you havem't gotten any stacks of Impure Shots on someone. This means that you shouldn't use your ult in fights, only use it to kill runners.

Miss Fortune is very easy to farm on, with impure shots giving bonus damage it's easy to push your lane up and your Double Up is very good at killing 2 minions at once. Early Game you don't want to use your abilities to farm very much, however as it gets later into the game you can use abilities to clear entire waves in seconds. In lane I would suggest letting the enemy push you while you only last hit minions then ask your jungler to gank. If your jungler doesn't gank use Q once and W once to clear the wave quickly and reset it, then repeat this process.