On a new lake, I bring my Navionics on my Cell Phone and plop down near the others in the area and see how the bite is. As a starting point anyway. Then I look at the structure on the map as to why these other guys are there, then look for spots on that lake that are similar in depth, bottom makeup and structure. I catch a fish now and then too! Also, some sports shops will share some nice info too. Navionics guys will often share hot spots within the mapping app publicly too so check into that.