Pick your best champion/role (Make sure you know all the roles decently) and carry your team, buy wards (Doesn't matter who you are, pinks/greens) grab a sweeper after 9, make sure you are the ward machine and pray to the gods of rito that you can actually have a decent team, if your leaving the base with 75 gold, your doing something wrong
I'm currently trying to climb out, facing the same problem, literally 4 games in a row nothing but trolls and little kids (I mainly only play during non-school hours for this reason) I do decent, protect the base, farm usually have the highest farm on my team, low death ratio, push objectives, roam, then... I get a sona, or a jinx, or whoever who literally thinks its fine to rush their jungle, with no wards and our base being pushed, or a jinx calling for drag... as they are sieging our inhib tower. or my favorite, a jinx/sona bot combo... sona misses one ult, jinx rages at sona, sona then proceeds to throw the entire game because "Teaching this jinx a lesson" or an amu, who after getting pulled in by an obvious bait, while we're all pushing up towards him, cries, whines and continues to split push the entire game (This has been a few of my past games) or a fiddle... who constantly rushes head first into the enemy nexus... at level 1! or a "Support vel" who was last pick... and afk in base for the first 5 minutes, feeds mid 2 kills, goes roams top 2 kills, and just states "Gg we lost"
keep pushing, don't get discouraged you'll eventually find that good team to push you out of bronze and into silver... which is 1/10th better than bronze, then if your good enough again, you'll eventually be pushed outa silver into gold where you've successfully increased the overall playerbase by around 15%, the grind is real, we all feel your pain :(