I understand that there are a lot of players at very low elo's that are more skillful than their surrounding team mates and opponents who are frustrated at the fact they are constantly trolled and feel as if their win loss ratio is outside of their control. As a summoner that was trolled down to 400 elo last season, I feel your pain.
In the past 3 weeks, I have carried an account from 600-900 elo and I am continuing to rise day by day.
In this guide, I will explain what it takes to get out of elo hell.

It may seem ridiculous but mentality plays a huge part of getting out of elo hell.
You must first except these ideas, then you can go forward with this guide. If you simply dont agree with these ideas, stop reading the guide. If you can't accent these ideas, the guide will do you no good.
1. Both teams have trolls/baddies
A weird misconception is that only your team has bad players. Its simply not true. Getting out of elo hell is all about capatalizing on the enemies trolls/feeders. In this guide, I will show you how to do this.
2. Stop blaming teams, start blaming yourself.
People constantly blame their team "jax feeder gg," but in reality, you need to blame yourself if you lose. You didn't carry hard enough, capatalize on the other teams bad players and do what it takes for your team to win. Hence your loss in elo.
3. At this elo, it is a solo game, not a team game
Stop relying on your teams to do everything. If you want something done right, do it yourself.
If your team helps, cool, but don't rely on them.

Pick a noob stomper champ.
I do not believe it is possible to get out of elo hell with any support with the exception of blitz, so try not to be support.
When I say noob stomper, some examples are akali, katarina, draven, olaf, yi, xin, etc.
Those champs do not function well at high elo play, but wreck at low elo's.

This is where we separate how to win at high elo vs how to win at low elo.
Lets say you are Caitlynn and you are not doing well early game vs Ezreal. Rather than continuing to fight ez despite the fact that hes already doing well and he will probably kill you, you should instead go b and look at top and mid and see which of the enemies champs are doing bad. If they are in a place where you can gank them, do so. This way, if you get a kill, you can go b perhaps start to keep up with ez, or if he escapes, you can go back bot where ez only has only gained a few cs while you were gone.(People at low levels generally aren't good at csing.)
Whatever lane you are in, you should be acting as a secondary jungle, especially if you are mid. (Its all part of that "dont rely on your team" mentality.)
To be continued.

Teamfighting is once again very different at low elo's.
Once again you should not rely on your team.
For example, if you are an very tanky offtank, you should still behave as if you are very squishy. This will ensure you stay alive as long as possible even if the feeders on your team die in the process.
Adcs should come to fights a little later. They should not be near the teamfight from the moment its initiated.
Mids should also be playing it safe.
The only people who shouldnt play it very safe are overly tanky tanks like mundo. Remember, the feeders on your team will act as fodder while you sit back and play it safe and do tons of damage.