Hi roger121,
The good news is you are in a great spot, and you have a good shot of improving your score. Thus, engaging in topical practice for GMAT quant, verbal, and DI is a great way to move forward.
Let's use quant as an example. Let’s say that you want to practice Number Properties. You can do so by answering 50 or more questions just from Number Properties: LCM, GCF, units digit patterns, divisibility, remainders, etc.
After each problem set, thoroughly analyze your incorrect questions. For example, if you got a remainder question wrong, ask yourself why. Did you make a careless mistake? Did you not properly apply the remainder formula? Was there a concept you did not understand in the question?
By carefully analyzing your mistakes, you will be able to fix your weaknesses efficiently and, in turn, improve your quant skills. Number Properties is just one example; follow this process for all quant, verbal, and DI topics.
Feel free to reach out with any questions.
Good luck!