Statikk Shiv Thresh

I am really bad at playing . I consider playing Lissandra, Ahri, and Riven to be fun, challenging, and easier than playing Thresh. I just suck. Plain. Period.....Until I decided to build him with Holy shit. I started doing a lot better with this item. The problem I faced with Thresh was not that I couldn't land a hook. At best I'll land it 8/10 times (pfft more like 7/10). The real issue was that if my team was behind, I would completely be useless. I would play burst mages like Annie or Syndra as a support so that even if my team was on the losing end, I would still be able to help out and take down so foes or even wave clear fast enough to either push a lane or protect a turret. For me, I was not able to do this as Thresh. However, I can start to see why other players would sometimes play him as an adc. Are there any tips you Thresh mains can lend to me?