Record your replays then analyze what you could've done better. Whether it be early jungle paths, gank paths, teamfighting, decision-making, just be critically harsh on yourself (and ignore what your team did). Can't really tell you much about jungling. I know the basic concepts, but I know nothing of matchups or the very small details. Oh, one tip I can give is before every game (or before the day), choose one concept/skill to focus on and just work on it, win or lose. For me, it was melee orb-walking, then balancing trading and CSing, then map awareness, then CSing in the first 5m. Well, I those are what I remember. I think there was a time where I focused exclusively on not dying, and I usually had 3 or fewer deaths for a long time with vastly improved decision-making. You basically want to accumulate these skills and improve yourself one skill at a time. My map awareness is still bad, but it's good enough and when I'm really focused it's pretty good (because I'll focus more on decision-making and that will force me to ask questions based on what I see on the minimap, so I'll look at the minimap frequently). The idea is to strive for optimal play. Yes, playing perfectly won't win you every game, but it will drastically increase your winrate, which will make you climb faster.