SAT Writing Section - Tips please

My current method for the writing section has been to choose whatever answer choice I see fit (I’d like to think I have a good sense of the grammar rules), then checking with quick tricks/rules I’ve learned from SAT Prep books. However, I could understand how this may not be the most efficient or effective method. Opinions please?

(For context: I got a 720 on my last SAT test, 2 wrong in writing, but of course everything counts, and I don’t know what I’m missing)

Look at the questions you got wrong, practice more like those questions, make sure to memorize all of the rules. Don’t even use an SAT prep book, buy an actual grammar book.

Your method sounds fine. Just practice a bit more so you’re comfortable doing everything fast and within the time limit.

Eliminate whats wrong and then use your writing skills