dead smelt 2' off the bottom...or (if legal) most prolific indigenous forage. I start with smelt (easy, cheap, and easy to transport. Then I jig for smaller perch and gills and change them out as I get the right size. I normally raise the bait further off the bottom closer to ice out. I think they cruise under melting ice to find winterkill falling out of the surface ice and have actually seen fish almost touching the ice cruising under my holes. I've always been curious if it's O2 level, spawn, forage, or what that makes them do that. Could be a combo of all 3 I guess.
One thing I found with live bait - use a bead, clevice, and large willow leaf hammered silver spinner about 3" above it. Doesn't take much action from the chub to get it to flash and it pulls fish in from further away IMO.
