Good tips. Look at picture #2 - the Duck and, "Not getting many signals? Try under logs and places you normally wouldn't look."
A few snows ago (in the summer) I was detecting a Boy Scout camp with a group. I passed between 2 trees detecting, and DIDN'T detect over
a flat 1 foot by 1 foot flat rock. A buddy following me did detect over the rock and got a beautiful Franklin Half which was underneath the rock.
I learned a lot.