I agree that players seem to have a difficult time understanding basic wave management. But it's actually not that difficult:
_**Push the wave to enemy tower.
Anything else is most likely a macro game mistake.**_
Some of you are like "but, but sometimes you should leave it and sometimes you should last hit it and sometimes you should blah blah blah"
Well guess what? All those actions require players to understand wave mechanics. And don't get me wrong, junglers should learn wave mechanics too, but for whatever reason many players find it difficult to determine the precisely technically correct thing to do in game.
On the other hand, pushing to enemy tower is almost always the best thing to do and almost never the wrong thing to do. Any other action on the wave is potentially the worst possible action that can be taken.
Why is this? Very simple. Minions are the primary source of experience and gold in the game. Securing that gold and experience is vital to your team's success and is your team's primary objective in early game. Denying gold and experience to the enemy is equally vital. Any action that fails to secure vital gold and experience in the early game is almost always a mistake.
Some of you are like "but but, you should listen to the laner". Well guess what? Laners don't always know the best way to manage waves either. For some reason wave mechanics are so hard that even laners have trouble doing the precisely technically correct thing to their own creep waves!
I know it sounds ridiculous and some of you are saying "well let's just ask some high ELO players and do what they say". Well guess? That's right, even high ELO players have trouble with wave mechanics! Apparently wave mechanics are so difficult that even high ELO players have trouble doing the precisely technically correct thing!
In end what low ELO players need is something that solves the majority of wave management issues without ever being too bad a thing to do. The answer is simple:
Farm that wave of all of its gold and experience. Your team needs it the enemy team needs it. Letting it go to waste is definitely the wrong thing to do in early game.