So I didn`t play Fizz that much. And I`m not that a good a player at that but I`ll still try to make a guide. Be nice on me It`s my first one^^
I`ll try to do my best and I just want to know your opinions on this guide.

So in the early game you should wait until you`re lvl 3 and have all your 3 skills. If you have enough mana just go in with E, dash onto the enemy with Q activate W, hit him and mark him with ignite. It should be first blood. But be careful when plaing against a caster on your lane. Those are the only enemies that were difficult to play against for me so far.

In the Late-Game just jump over the tank and attack the AD-carrys. They should fall pretty fast to your burst damage. If you`re in a teamfight and see that a teammate of yours is fighting 1on1 with an enemy just use the range of your ult to throw a fish at the enemy to support him.

So I think this is known to anyone but you need to learn where you can jump over with your E. It is not as good as flash but it`s very good for stealing dragon or baron.

Also of you engage against something like Morgana or Brand jump over their skillshots. Put on the old Poker Face and dodge everything :D

Now you should know that your Q dashes hrough the enemy to the last border of it`s range. It`s pretty usefel when running away from things.

And always remember that when you`re jungling (Baron, Dragon or buffs) position yourself next to the cliff. Don`t use the E to deal damage. Save it if you have to retreat.

For runes I just used the standard caster runes. Unfortunately I just have AD runes right now but it still works good^^

I use Flash and ignite because I just feel saver that way. You may don`t need flash because of Fizz`s E-skill but it has a lot of cooldown so you should have something that you can rely on when E is on cd. Ignite works good with fizzes passive of his W-skill but I played with stuff like promote or Ghost too. I think that promote is not that useful in the Late-Game then again ignite isn`t either. I think that you could get exhaust and maybe surge (If it is viable, I don`t know) to become a mobile tank-killing unit but you have to test that out for yourself.

So that is my first build. I hope you like it and if you don`t please, PLEASE feel free to criticise but when you do give me tips what I can improve.