I am assuming you are talking about fishing this open water. If you can get out on the lake with a boat, I have found that with pre-spawn cold water walleye, the best presentation is with a very slow presented light weight jig (ranging from 1/16 to 1/4 oz) tipped with a minnow can be killer. We usually vertical jig, right off the bottom and actually move the jig by motoring around with the electric motor. Sometimes when the water is cold, you have to get that bait right in front of their nose. The take is usually very subtle and might just be a light tick. Set the hook every time you feel the slightest bump on your jig. We have also done well using a lindy rig tipped with a phelps floater and a lip hooked small minnow, especially if fishing from shore. These pre-spawn fish are usually very hungry but can be fairly lethargic in the colder water. Patience and a slow presentation are your keys.
IceTroll