If you have an untamed nether region I'd suggest using scissors to cut the hair pretty short before going at it with a razor--keeps the blade sharper and doesn't take as long.

Try to keep the skin taut for a smoother closer shave. Use shaving cream or hair conditioner (slick, effective). Shave with the grain or perpendicular, but if you go against you're more likely to get razorburn.

Use a brand new razor.

Go slow!