When you are out on the ice, remember that the water is very cold and the fish while still eating are definitely not in the mid summer activity levels.  To that end, they often look for an "easy" meal, and often that means small presentations. 

Last winter I caught my biggest walleye ice fishing on a 1/16 oz Lindy Frostee Jigging spoon with a wax worm.  All the guys around me were catching small walleyes and perch, and I pulled in the largest one caught that night.  It seems counter intuitive, but it often works.  For walleyes getting down to 1/16 oz definitely shows them a different presentation than they are used to seeing.  For crappies and sunfish, don't be afraid to try micro jigs that are 1/64 or even 1/80 oz in size.