They give you more wins in your series the more often you go up for promotion. I failed my first Gold series and then the next time I went up for it I was given one win. I then queued with some friends who were bronze during this second series and lost it. When I solo queued I climbed to the Gold promos again (3rd series) and they provided me two wins. I am not sure if in the sub-divisions do this as well or if they simply automatically promote you if you keep entering a series, but it should be easier the more often you go up for the promotion.
If you keep achieving it, you don't belong in that Elo and it is only a matter of time. I originally placed in Bronze I this season after achieving Gold V last season. I was able to easily get up to Silver III with no real issues, but it wasn't until I found a reliable ADC duo partner that I was able to move up into upper silver (I main top).
Depending on your role and your champion, I think is it more challenging to climb than last season. I think in lower Elos, the mid lane is the most important role and the easiest to carry. I also think the easiest way to climb is to play ONE or TWO champions over and over again. You will get very good with that one champ and eventually climb out. Too many lower elo players have a large champion pool so they never develop consistency with a main. They spread their talents across too many roles and too many champs resulting in relatively mediocre play in each role.
They also do not take objectives or rather they do not prioritize them over kills. Objectives are more important than kills so playing a split-push champion may help you more than grouping with the team and having uncoordinated team fights. Bronze players also are really bad at minimizing mistakes. Playing conservative and passive can lead to good outcomes since in that Elo mistakes happen A LOT. Last season I simply climbed by reducing mistakes, and playing good mechanically. My team fight is still garbage and I didn't develop any greater understanding of the game. I just tried to minimize my deaths and I began to use teleport a bit more often.
If you keep going up for promos you should eventually climb out of the divisions. Good luck and I hope this helped.