Best way to improve in LOL?

watch your replay and watch pro games you also have to learn the matchup

watching pro player, testing every champ and playing ranked

Play more, watch some twitch streams of people using the character you want to learn, and also watch the current meta of the game

I would saay just playing. If you want to get better fastfocus on one champion so you can master it.

I would say the best way to improve would be to watch your own replays, but not just for the sake of watching them, you have to know what you're looking for, so you need to inform yourself first, that's where Youtube guides like Mobalitycs and Skillcapped come in handy, besides watching your own replays and watching guides I would personally suggest to play a lot of games, have a champion pool of fewer than 4 champions (oneap, one ad, onetank, and one bruiser) and keep it simple, don't play overly mechanically complicated champions like Lee Sin or Nidalee. Hope that helps!

i dont play the game, but the best way to improve is to play the game

watch ur demos, and play on 1 lane

Just keep playing and posting and eventually youll get good. Or be like me and watch youtube tutorials and competitive players.

Practice is key, the more time you put in, the more you get out. Also doing post game analysis

I haven't played League in several weeks lol, but when I was trying to get better I would usually just watch guides or youtubers. Even now that I don't play the game, I watch this youtuber named Neace. He does a lot of coaching and has some guides, even if you don't want to learn the champions he's playing, he's the self acclaimed King of Macro play, and it had definitely helped me.