racing is a constant struggle if and when you start to do well.
you find your speed where you are consistent and are doing well but still not fast enough, so you try to push harder and end up crashing, so you then think a setup change will help, so you change setup and then sometimes it will help ever so slightly but sometimes you start going backwards! its all part of it.
But in my opinion nothing works better than practice.
I personally found at my local track that after x1 sat practice day of taking notice of what lines I could take fast and what lines I had to slow down for I started to make it into the A main instead of lower finals on the race days after that x1 practice day!.
don't get caught up in setup is my advice, as yes it can help but not as much as track time will.
also your mind-set changes when you start to do well, from just having fun to wanting/expecting to do well every time you race which in turn takes all the fun out of the hobby if you ask me.
I have not been practicing as much this year as I used to and now its like everyone at my local track has got better and are starting to do better than me, but the fact is that they are racing more than I have been this year.
so practice practice practice its a vicious circle