Most of the time start above the fish, the active feeders and aggressive fish (bigger) will be above the bottom huggers. This is especially true of crappies. Walleye will normally be close to the bottom. Sunfish can be anywhere but mostly closer to the bottom. I start just below the ice and work down in less than 20 ft. Of water. For basin crappies half way up but watch for marks above your bait on the locator. You will be surprised at how far active fish will rise to take a bait. Remember the distance below your bait that the fish show up on your locatator. Try and keep this distance between them and your bait, play keep away. Prey won't chase preditors.