One other bit of info that I got when I first started that has helped me in hunting (especially with the older gps units):
Give the coordinates about 20' of leeway, especially in dense cover. So if your gps is 20' off and the hider's gps was 20' off, you have a 40' radius of search from ground zero.
If you are still having issues, walk about 50-100' away and come back in. That may give you a better idea of where to zero in. Also, stop, close your eyes, and take a deep breath. When you open them, don't start searching, just look. I've lost count of how many times I have done that, and the hiding spot just jumped right out at me.
Most of all, just have fun. If you don't find it, just take in the surroundings and enjoy just being outside.
~ynomrah~