There's honestly some pretty good examples on here. The biggest point I guess I'd make is, you don't ALWAYS need to be on the tower. Tower can be tricky, especially on ranked. Not many people ever want to get on the tower because they don't want to die. If you brave up and get on, pay attention to your teammates, and the people around, you can often get a decent way. Watch the enemy team as well, if they're 2 teammates down then often times that's a good time to push. Try to fight for the tower before getting on, and when enemies re-spawn, play a bit more defensively. Don't HUG the tower, but definitely do your best to keep it's current placing if you can, and try your best to get any possible teammates to help get on the tower or push it as well if you can't. tapping "this way" sometimes can really be useful!