How to do reading passages? Please help

Should you read the questions before or after reading the passage? In the reading section, I read the passage, more so skim it, and then write notes about main point, topic, paragraph purpose, etc. Then, I do the questions. How should I improve? I am stuck at 690 in reading, want to get at least 740.

I had some trouble with the reading on the PSAT too. But I think that writing notes as you read the article then going to the questions is best.