How to climb/improve at league fast?

Hey guys I just want advice from higher elo players that would help me climb and become a high elo player myself one day. Little background on myself, I played dota for a little bit so I came into league with a good idea of how the game works. I haven't been playing for too long ,so I understand I obviously must not be doing certain things which would result in the current elo i'm in (Gold 4). Now I'm well aware of google so I read up on a majority of things to work on.

For example -last hitting -map awareness -overall knowledge of champions (skills etc.) -knowing how to effectively snowball -mechanics

I try to work on all of those things,but I myself work just like everyone else and don't have time to dedicate to league to master certain things. This is why im seeking advice from higher elo players to make the short time I play league effective, so I could improve a lot faster. I play mostly mid or top, but wouldn't mind playing jungle as well.

So I'm basically looking for any tips that would help me improve really fast.