Doing old regents is really the best way. You learn to take a regent and get used to the sort of questions that are on it, and know the teachers test. Many teachers use old regents as a guide when making up tests. It will also teach you the course once you get the hang of the questions. You can time yourself, and improve your goal so when you’re actually at the regent, you dont feel as pressured.
For english, you can use anything, not just major works. Megillas Esther is ok too. (supposedly)
Hatzlacha!