Perhaps I should start. Cold water such as ice fishing or first ice out requires very slow jigging. I like either a cast master with a mousy or very small mill worm when fishing through a hole in the ice. A close second would be a 1/16 ounce jig with the same bait to sweeten it. I usually jig it a few times then stop. When stopped I get most of my bites. I sometimes use a small bobber when jigging so when I stop jigging it will move just slightly, set the hook! Problem with the bobber is you need to reset the depth if you reel your line in.
Early season cold open water I usually use a bobber with a 1/8 or 1/16 ounce jig but no bait added. I adjust the depth until I find where many of the crappie are located at. After a while I may re- adjust the depth when the bite slows down. I really like a silver- Nickle plated head with some white calf tail. At times depending on water clarity i do change colors such as yellow or even some greens. I have fished the Chickahominy river in Va and found that a orange head and calf tail works best in high off colored water.
As water warms a few degrees I usually cast 2 jigs and sometimes using a 3/16 ounce for one for a little more weight and casting distance. The fish will start to be a little more aggressive so the medium slow retrieve works well for me. When water temperatures warm a few more degrees a faster retrieve can put more fish in your creel at a quicker pace. Also some larger lakes will have streams large enough to pull spring crappie to the warmer water when sunlight can penetrate and this can be a magnet for a spring run and spring prespawnd fish. I am sure some have other ideas and perhaps they work well for you so lets give each other some ideas.