GMAT club tests are one of the best test material to improve your Quant skills.
I was struggling at Q40 range and by the time I was done with the tests I was scoring around 47.
The question are quite tricky and I was able to improve my DS like anything.
The best way to maximize the output is to refer to each question from the test irrespective of right or wrong.
For every question multiple solution are provided so that you can choose whichever method you like.
Just in case if you are not able to understand the explanation ask "Bunuel" he is the god of quant.