How the heck do you split hackle stems?  Sharp razor?
 
kjh, That red/purple fly is sweet.  I'll take 2!

after soaking for a bit... i strip a side and usually that takes a good amount of stem bulk with it

ORIGINAL: SonofZ3
 My father ties a caddis emerger that I've never really tried to master, he uses benecci 12/0 or 10/0, splits it with the point of his tying scissors and uses the split thread to make a dubbing loop.

I tie the little dries when I start to run low, but they're really his thing. It works out good though, I do all the streamers/salmon & steelhead flies, and he makes gorgeous little usual emergers.

 
heehee, good partnership.  I can admire splitting thread and all that, but no thanks at my bench, you know?

Cold: you probably already figured it out, but when tying full feather wings it helps to flatten the stems with needle nosed pliers. They tend not to roll as much.

GP crest: different sized glasses/ mugs are good for shaping gp crest. set the mug on its side, dip some fingers in water and use the water to stick the GP crest on the mug. the water will stick the crest to the mug, and you can straighten it out and give it a nice gentle curve.

Thanks, SonofZ. Yeah, I do that with the full feather wings. :) Learned that trick from this site.

The GP is more of an issue of how to get those individual fibers to hang down instead of staying all in alignment.

I've been consistantly overhackling spey flies lately!