Hey mconchab,
How are you on the time front? Do you finish the Quant sections with time to spare?
If you have time to spare then it would be recommended that you go slower on the problems. If you have time constraint as well then you might need to look at the type of problems that you get wrong. You need to do a SWAT analysis topic wise and get a feel of areas of improvement.
Needless to say that you need to practice a lot of problem.
Have a look at our
GRE Official guide Quant directory.
Best Wishes