Congrats on the cams, join the club you're now addicted...

Don't have any commercial cams, mine are all homebrews so you might get better feedback from others who own the Moultries.

1. I put my cams as close as I can, anywhere from 3-8ft away from where I expect activity.
2. I put my cams from 6 inches to mid thigh off the ground, depending on the perspective I want.
3. Over scrapes my cams are usually 6-7 ft or as high as I can reach with out ladder help.
4. If you are getting blank pics try pointing your cams down, rather than across a runway. This may help a slow trigger.
5. Clear any thing that might blow in the wind, tall grass, small limbs, leavesetc, so the motion when windy doesn't trigger the cam.
6. Try to face the cams North or South. Should reduce whiteouts and false triggers
7. Be creative. There are no hard fast rules that I have found re: cam placement. I have gone as far as to mount a cam to a discarded Xmas tree if no tree was present and the spot was screaming for a trailcam.
8. Double and triple check to make sure your cam is set to take pics. If you haven't screwed up yet don't get cocky. I will happen trust me. If it doesn't you should start wearing sandals because you're perfect.
9.Keep your batterys fresh. Lots of strange things happen with weak batterys and trailcams.
10. Clean your glass each time you place your cam. Can help with blurry pics. Quick motion of the subject can also cause the pics to blur. Just part of the game.

You'll get a ton more suggestions which should help. These are just a few off the top of my head. Good luck and have fun.....don