Just stick to meta champions like Cassiopeia and AD carry like Aphelios but I suggest going Jinx in low elo. If you're playing on low elo (Bronze - Gold) then I suggest that don't ever trust your team mate at all. Don't take bad teamfights just because all of your team mate did. Avoid playing support because it's hard to carry if you're not using champions like Brand. Learn the game like wave management so you won't die a lot and you won't miss exp/gold. I climbed using this in my smurfs, from Bronze to Master. My last tip is to itemize depending on the opponent, don't just follow the same build every match.
NOTE: I am also a solo player.