Support players, can someone tell me where and how to ward?

So I play nearly every support in the game and I've never truly learned how to ward. When I start I'll have three wards so I ward the two bottom bushes and the one leading up to dragon. I'll continuously do this occasionally warding tri-bush and when we all group at mid, I'll ward baron and dragon. Is there something more to this? Will someone on ranked kick my ass for doing it wrong? Help.