If you can, try to get a role that is easy to carry with once you get a few kills (preferably mid or ADC. Top, jungle, and support could work, but those two are easier to carry with). Also, try to play at least 4(pref all of them) roles at a decent level and get at least two champs, maybe 3, that you could play in each role.
Another important thing is attitude and mindset. You got to be positive not only to yourself, but to you're teammates. Just type in chat "Hey, we got this" and try to take command. If you guys keep getting picked just say "try to ward our jungle and stay together." Bronze people probably don't know what to do so it can be assuring if someone knows what he is doing. Also, if a teammate is being salty af to you, just mute him. No point arguing or listening to someone who won't provide any useful information. If he is being salty towards a teammate, just defend the teammate a bit and maybe give some tips to the victim in a constructive manner.
Also, about ELO hell. I don't believe in it, but I do believe in losing streaks. If you find yourself in a losing streak (like 3 games in a row or in a day if you're grinding), just stop playing ranked, play probably a normal, ARAM, or just stop playing league. Go outside, read a book, fly a plane, just get your mind out of ranked. As soon as you feel comfortable and reset your mind, just hop back on.
League is about self-improving too. If you can, download any recording software and record your games. Watch them and see any mistakes YOU made, no point seeing what your teammates did wrong, never going to see their faces again. Try to analyze this and avoid them in any later games so that you can become more consistent and perform better. This tip can be used in any ELO, but bronze is the best one to use it for.
