Teemo top is an odd pick in ranked. In my book a good Teemo top means a few things. You will mostly win your lane as long as its 1v1. Your dueling kit + ignite makes sure of that. Your mushrooms will make sure you will always have 100% vision of the map, reducing the risk of getting caught in a nasty gank. You can make crazy pushes with your shrooms securing a warning and an escape route, and when ignored this yordle recks some heavy ****.

As teemo you must always shroom on key points where junglers will pass, or where enemy walks to come stop you from pushing