TExES is another of the fine products from out friends at NES. Looking at the documents online, it appears similar in breadth to CSET Math. That is, it covers algebra, geometry, trigonometry and elementary calculus. It does seem to omit some of the more esoteric subjects we have to deal with in California, like group theory, though. The Texas folks are lucky in that they get to use a calculator throughout. Actually, some of the questions are apparently designed so that you have to use a graphic calculator to answer them. Apparently they only have to pass one exam. And I didn't see anything about constructed response questions. So, all in all, my guess is that it is a bit easier than CSET Math.
My guess is the same approach that works for preparing for CSET will work for TExES. But, of course, it should be tailored specifically to what is being tested. It also means that there is no free lunch. There is no useful review guide for CSET Math. And I doubt you will find one for TExES. The best I can do is recommend that you check out the threads on CSET Math in this forum and do lots and lots of practice problems in the areas you are having trouble.
FWIW if you are making the same mistakes over and over again, it is time to do something different. Which domains are you having trouble with?