A "proper" catskill requires hen hackle tips to create the wings, you don't split jack in so much as you tie in two seperate tips, one at a time.
Its alot of work, and alot of dead chicken feathers.
Start with tying a Wulff style hair wing fly.
Get a calf tail and a size 12 hook. Go big. You'll use these to float your silly little nymphs so don't worry that you'll never use a size 12 Royal MF Wulff. You will. You will see the light.
Take your clump of calf tail (trust me, use calf tail rather than whatever someone else tells you). Cut more than you think you need, flip out the short stuff, and stack quickly.
Tie it down midshank. Wrap wrap wrap.
Now you're at a point where you want your wing to be, right?
Pull it up and then back, and wrap wrap wrap a "thread dam" in front of it where you're pulling up, right up on the point where you've pulled it up and back. Let go of the pulled back wing and, biggity bam!, its held up in place (see, "thread dam").
You've made an unsplit wing. Lee Wulff said this was better, arguing with him is akin to aruging with a fat guy about the merits of MSG, so just shut up and do it.
Now wrap back and tie in your body. Enjoy.
When you've done that and you're satisfied with unsplit wings, try to split one. do the exact same thing, but split it fitty-fitty. Do some X-wraps between the split, going so far as to wrap AROUND half the split, each wing's base, a time or two to get a nicely defined wing. Remember to pull BACK on the wing while you wrap, it'll make it stand up.
I'd take a picture but I'm lazy and some super awesome net.hero will steal thunder by making a video, so just wait for that anyways. It'll be super-awesome so credit assuringly.
When you've got the calf tail wing, try it with mallard flank fibers.
To hell with hen hackle tip wings, too much effort and dead chicken feathers. Honestly, unsplit wings work just as well, remember fat guys and MSG.
