I'm a casual League of Legends player, and I recently started playing the Champion Fizz, I really enjoy the champion and seem to do very well with him, I thought to myself one day, "I wonder, would anybody else find my experiences useful?" So Here I am, I'm not a ranked player, nor am I anything special, I just thought my insight on fizz might be helpful to someone new to Fizz.

Personally, I'm not picky and have very few runes, just get some Magic Pen and Pure AP if you can.

Early: It's best to Charge in with your Q, Pop your W and beat on them until they begin to unleash their fury on you, Bounce away with your E twice and if necessary, flash away and repeat.

Mid Game: If you have your Lich Bane, Q in and Basic, W, Basic, if they begin to run, Bounce onto them with E and Ult them away!

End Game: Q in, and Annihilate them with the fury of Fizz!

I suggest Flash and Ignite because it makes it easier to Kill Secure and get away when your E is on Cool down, but Ghost/Exhaust are both good options.

Due to you have no unit collision, wait until the minions are almost dead, and walk up/Q them for the CS, that way you can avoid enemy champions as well.

Pros:
Easy to Kill Secure
Easy Farm
Easy to Escape
Massive Burst Mid Game
Hard to kill
Really fun

Cons:
Mana-hog
Squishy early game
Long Cooldowns
Easily Countered
Short.