Atomic Poision Ivy is a solid top laner and can handle herself well in teamfights. She has superior move speed and her skills allow her to save her teammates or set up a kill. 

Amp set-up-
I take amps based on armor per level and some power effects with cooldown per level.
The mods are
Quicker Medisys on Medusa Mask
Altered Qward Gambit- gives credits at tier 1
Extra Attack Armor on Fragment of Mogo


Laning- (Enemy Full or High HP) I take the E first in order to slow the opposing laner and their drones. It has amazing range, and can be used under the turret effectively. The W is used when the enemy dives you or when you just want to kill some drones. The Q is a nice AoE skill, not spectacular in damage but has great cooldown. Here, you just want to damage the other laner and keep him/her from healing.

Laning- (Enemy Low HP) I wait for the other laner to get close, then E and catch them in it with the W. As API, you can basically sprint towards him and activate your Q. This will give you extra move speed by consuming toxic growth and let you stick on him. I am usually unable to get the kill, but can make them go back to base. I'll explain why that is OK soon.

I usually end up losing my turret because API cannot kill well while solo. Getting ganks are important, but not completely necessary. I play API to make the opposing top laner to back to base and gank middle while he's gone. Because to me, helping push mid lane is more important than taking  some damage on top turret.

Teamfighting- I try to single a squishy character out with my huge range E and freeze then with W. My teammates then do the rest of the work as I tank the other enemies. Here is when the CDR from Amplifiers, Marauder Ring, and Booster Gold Suit are highly effective. Being able to freeze a character twice or three times in the same fight before there is a retreat is phenomenal when peeling. The E and W are great for chasing and fleeing the fight. Also, don\'t be afraid to dive turrets for a kill if you have teammates behind you. The Cosmic Staff added with the Decaying Damage of your E will keep the turret focused on you while your team destroys the enemy turret worshippers who stand there thinking they are safe. Show them the error of their ways with your immense health bar and shield with Booster Gold Suit going to work. You\'re Ultimate is amazing for hiding your teammates behind you. Initiating with this skill is highly effective when you have a Marksman on your team. You can slow and freeze the enemy while your Cyborg blasts all he wants at them in stealth. 

API is a bit lackluster in damage by herself, but can survive amazingly well. I was once able to sit in the AoE health drop and tank a Gaslight Catwoman, Gaslight Joker, and Nightmare Batman until my teammates finally made it over to me. I had a laugh while running around in circles and slowing and freezing three people at the same time. I have a lot of fun playing API, and I hope you do too.