What's the best way to catch walleyes under the ice and with what tackle?
Tight lines.

I don't know what's best as it seems to vary from lake to lake and time of day. I go through a variety of techniques like rattle spoons to standard spoons, rattle jigs to standard jigs, and most of all rattlin flyer spoons or flyer/airplane jigs. The most deadliest of them all is the plain old deadstick minnow on a round 1/8 or 1/16 jig or forage minnow.

Hmm... well I do already have quite a few of those "Frostee" jigging spoons for perch, so those might work. And I have plenty of standard jigs for open water season. I guess I'll try those.
Tight lines.

Jig and a minnow here. Glow white jigs worked best for us last year. Occasionally we'll throw a Salmo Darter or Swedish Pimple down the hole to get some action if we're icing for lakers....but mostly minnows for walleyes.