It works from ice-out to ice-up. The only change is during the heat of summer I fish deeper beneath the strike indicator, on the outside edge of weedlines, or even out over open water.
So, here's what I do. I usually use a 9' 5wt fly rod, with a 5wt Weight Forward Floating line. I used a 7'-9' tapered leader, and at least 3' of 8 lb test tippet (3X). I could use lighter tippet, but the fish don't seem to be line-shy, and I've had my share of surprise encounters with large catfish and bass that would not have been landed with lighter tippet.
At the end of my tippet, I use a No Knot Fas-Snap, size Medium. I like these because I can change flies quickly in near darkness (or anytime), without having to take the time to retie a knot and shortening my tippet. It also allows flies to swing freely and move naturally in the water, similar to using a non-slip loop knot or Duncan loop knot. I've used the Small size, but have had them bend open too easily on larger fish.
The fly pattern I use for this particular technique is a microjig. A number of colors will work, so experiment with your favorites. One of the most consistent producers is Chartreuse. I usually use chartreuse grizzly marabou for the tail, but solid chartreuse marabou or rabbit fur works great too. The jighead is 1/80th oz with no collar, and a size 10 hook. You can find great prices on these on eBay. The body is just chartreuse yarn...REAL chartreuse craft yarn, it lights up super-bright under a UV light. Its hard to find. Dubbing would also work. I use a bright orange thread, 6/0 UNI thread, but any color would probably work just fine.
Use a strike indicator of your choice. My current favorite is the Fish Pimp original size strike indicator in the bright yellow color. Their website has videos showing 3 different ways you can attach this indicator to your line. http://www.fishpimpco.com/
I cast out along the shores and drop-offs, or beyond weedlines, or over submerged rock piles. Windy days are nice, as the waves pushing the indicator up and down impart great action to the fly, which the crappies find to be irresistable. Let the fly work in one spot for up to 10 seconds, then move the indicator 6" to 12", and let it set for another 10 seconds, and so on until you're in water that is too shallow. If the Crappies are especially active, a very slow steady retrieve will get strikes. The indicator just goes down or sideways.
That's its. It works great!
Here's some fish caught just in the past few days:
My friend Chad has videos on his website. One video demonstrates how to tie these microjigs, and in another video he actually demonstrates this flyfishing technique. He's even fishing one of the public ponds in my town! :) Here's a link to the page that has these videos.