Each of the two scored Quantitative sections consists of approximately 20 questions in 35 minutes, or 1 minute 45 seconds per problem. Also, GRE is a section-level adaptive exam, meaning that your performance on your first math section will determine the difficulty of the next math section you will receive. To get a difficult second section of math (you must get the hard section to achieve a top score), you must answer all or nearly all questions quickly. Since there is no penalty for wrong answers in GRE, you can always try guessing in some questions, it's always better than leaving it unanswered.
I would talk about some useful Quant strategies that a GRE aspirant should embed into his/her preparation to get (near) perfect score:
1. Use of Calculator - Since calculator is allowed in GRE, many people avoid using there brain even for a simple calculation like 2+2. This instead of reducing the time taken for solving the questions, increases it. Please try to avoid using calculator for simple calculations & try to calculate as much as in your mind as you can. This will take much lesser time.
2. Time allotment to per question - On an average, 1 minute 45 seconds is the time that you can take on each question. Let's make it a little more easy & you can take as much as 2 minutes/question, BUT, than you have to do some questions in less than 1 minute time (which is very much possible). So try to complete the easy questions as soon as possible.
3. Information given - Try to thoroughly analyze each & every information given in the question as every information is important & leads us to the answer.
4. Word Problems vs. Direct Problems - Direct problems generally don't take much time, but be very careful with word problems, which can be tricky at times. Please read every part of the question carefully so as to judge well what exactly the question is trying to ask. Allot more time on word problems.
5. Options - sometimes it's much better to solve the questions from options. If it is possible, try to do the question from options than to do it the longer way.
6. You have the best method - Many people will tell you that this is the best way or that is the best way to solve a particular question. But it is you who know the best what is the BEST method to do a particular question. Try to stick to the method that suits you best.
some other points to remember:
7. Analyze tables/graph thouroughly.
8. Break Complex figures to smaller shapes.
9. Keep your cool.