i like using crankbaits as a "fish locator". i like casting a crank into areas where i think crappie maybe holding. if i catch a few in a spot i will generally downsize to a standard jig setup and fish the area thoroughly.
i've trolled with crankbaits, especially in water in excess of 10 ft. obviously with more baits in the water your chances of catching more are increased due to the fact that you can cover more water than with one rig. when doing this i like to use a heavier pole since trolling with crankbaits will cause a flimsy rod to bend a great deal.
i've used the following crankbaits Rebel crappie-crankr, Bandit 100/200/300, Strikeking Slab Hammer and Bitsy Minnow. i've used pink, black, chartrueuse, and white colors in any of the above baits.