I usually start shallow(4-10 ft) around brush and docks that has quick access to deep water. And as ragnar said start on the edges and work the entire water column and then move in. 5 to 10 minutes tops at any one place with no luck and I move on. After 4 or 5 shallow spots that I know should hold fish then I start going to deeper water. Where I fish I have around 100 waypoints of deep water tops marked. I will look at them on sonar to see if they hold fish....if not, move on to the next one. I strictly vertical jig and shoot docks. Single pole in shallow brush, 2 pole in deep tops if the action is slow. I also keep 3 or poles rigged up with different color combos of jigs. For example 1 will be chart/red/black, another will be smoke or shad color/chart, another blk/pink, last one some off the wall combo. Switch between the 4 nearly always produces some kind if color pattern. Usually it's a single color that triggers them. Such as anything with chart.
A descent finder with at least DI is a godsin.