cloudy, drizzle rain, and even windy days are normally more productive on clear water lakes. You can also fish the early dawn and late dusk periods of the day ... staying on banks or timber stands or submerged structure that is in the shade. That's not to say that you can't catch Crappie in the middle of the day, just that it's much harder then. Crappie will tend to drop down deeper in the water column, when the Sun penetrates to their level. They will seek out deep structure, which affords them a shaded hiding place from which to ambush their prey. They will generally hold much tighter to the cover, in the shaded area, if not bury right down into the cover itself.
For those times that you do still go to a clear water lake - be extra quiet and stealthy, fish the shaded water, face the Sun when casting to your target area (so as not to cast a shadow on the area), use your trolling motor and electronics sparingly, keep your distance from the target area as much as possible, use low vis line if necessary, fish slow and deliberate, use weedless jigheads to probe the weeds or timber cover, and ..........luck2ya ........cp