I agree on the idea of avoiding sandy soil, although I did not specify in my first post, my sites have a clay base to them and resemble Dbltree's in that they hold water for awhile after a hard rain.
Also, strategize on your mineral site location related to where you can put your game camera. In other words, pick a spot near a fencepost or suitable tree and have it face away from the setting or rising sun to avoid false photos triggered by the sun, etc.