For science, pacing is the most important thing. Period. Make sure you are adhering to five minutes or less a passage. Don't spend too much time on any one question. I didn't go over any general science, but on the April exam, for example, they asked a question about convection, radiation, and conduction in terms of heat transfer that a lot of people (including me) missed because we didn't know precisely what they meant. It might only be one or two questions, but a little science vocab review might help.
As far as reading questions first, then going to the passages, I didn't really believe in this technique until I tried it, so I suggest you do on some practice tests. I felt confused without reading all the information, but as I learned, it really doesn't matter. On the Charts and graphs sections, almost all the answers can be found by just reading the questions and looking at the graphs. Often multiple questions ask about the same pattern in the charts. It's a little tougher to do this in the experiments, and you have to read the conflicting viewpoints like a reading passage. Hope this helps!