1. Focus your attention on moss that is in the high water zone of a river or stream -- larger rivers seem to produce more moss and more moss with gold. The moss appears to trap dirt as part of its survival process when water is flowing over it -- usually during spring high water.
2. Moss and small plants like to grow into crevices and cracks in bedrock -- make sure that you thoroughly clean out each crevice below the moss. Use the wire brush to loosen dirt clinging to the face of the rock underneath the moss.