I would say the best way is to first familiarize yourself with the material (I would recommend Chad's Videos, especially for chem) and then keep practicing and reviewing the material with either practice tests or sample questions. For QR I suggest developing a problem solving mentality and knowing how to work through problems when given certain information, and this comes from practice as well. However I would take this all with a grain of salt given that I haven't taken my DAT yet (Tomorrow cannot be over quickly enough) but this is what helped raise my practice test scores in bootcamp