Cho consumes a lot of mana, so you should get something for it... I recommend the tear for fix it.
The mana problem will let you really exposed.
In early, you will need back to base for mana, get the faerie charm and some pots.
After that, go back to your turret really quickly.

If you are with some AD champ, "support it" using Ignite followed by RUPTURE taking advantage of extra AP from your mastery SUMMONER'S WRATH
So, you should be able to get it.

Engage with RUPTURE, then use FERAL SCREAM... If the enemy champ is not a tank, finish him with FEAST.