Reporting someone without playing game?

So how do you report someone without ever entering a game with them? Let's say in champion select some random kid as the last pick decides to autolock and call mid after we already have someone going mid. Or says that they are just going to AFK in game in the lobby. -Community is going to shit -Fix ELO hell (Can't seem to get away from this shit) -Gold ELO is also ELO hell? -FML.