Not sure what lakes you are mentioning when you say the metro area but I usually focus on weeds first, not necessarily a specific depth. Second, I would look for structure relating to those weeds like a point, hump, steep drop, etc. If you can find a point that had weed growth I would look for an inside edge or turn and start drilling there. I’m a believer the predatory fish move to the back of the weeds during low light so I’d be setup close to that back weed edge. On the Mpls metro lakes that’s usually 14-16 feet and out into 20′ before you lose the weeds.