Miss Fortune ability power is basicly based to solo lane and carry. The most important thing when you're soloing a lane is to always get the last hits on the minions to farm gold so you'll be able to buy your items faster.

Using Flash allow you to get in a good position to use your ultimate to get kills or either to teleport behind a wall to run back and using your Make It Rain to slow people.

Using Teleport allow you save a big walk to go back to your minions to stop the farming of your oppenents.

Getting Amplifying Tome and Mana Potion allow you to more dommage on your low levels than with Doran's Ring and to regen mana faster than with Doran's Ring.

Since your role is to carry, Mejai book is primordial. Try to always get the kills more AP you'll have.

Getting Sorcerer's shoes after Mejai is a good thing to chase people and also to dodge spells from your oppenents or to run back to your tower if they try to gank you. The magic penetration is better than the cd reduction because people will try to get some magic resistance items to counter you.