…that you have never done before to get it right before you tie the particular fly that requires it??
No I don’t.
Just fire away.
Nope! Just jump right in! May take half a dozen flies to get it looking right, but I figure, the fish don’t care! 
They don’t ??!!
I’m with the others. I just tie and if it looks horrible, cut it off and tie until it looks right. I guess in a way, that is practicing. You are just adding additional steps to the technique.
Hi Norand,
I absolutely never practice anything. I generally plunge right into the fly and tie until I get it right. Acceptability usually falls between 1-1000 attempts.
Normand, I’m curious. Do you practice? My guess would be no practice for you either. 8T 
Practice? That would be like homework. I didn’t do that either.
I just plunge right into the pattern. I sometimes cut off the errors and start over.
If I’m trying a new technique. Split Wings, for instance. After the third fly came out looking like … feces, I put a #6 Aberdeen hook in the vice, started at the back and just tied as many as would fit. Looked like a fly… nevermind.
BTW, they still looked terrible, so I’m gonna wait a while before I try again. At least until the frustration fades from my memory.
Kirk
Nope.
But then, I do have a single edged razor blade in front of me and my waste basket on the floor to hide the evidence. :lol:
Besides, that’s how I tyed my Royal Woof. It’s one colorful dog of a fly!
Normand,
Kind of depends on the technique. If it’s even close to something I’ve done before I just jump right in there. Make a few mistakes a keep those for myself. If it’s something totally new I’ll practice it on larger hooks first and work my way down to the size I’ll be tying.
REE
I practice new techniques all the time before I start on a fly.
It just makes sense to me to have the first fly I tie, look as good as the last. The practise also helps me develop my own methods which ultimately results in flies that take less time to tie.
I also do it so I don’t waste good materials. For example, when I first started doing married wings, I practised with some lousy feathers before I stated using the dyed quills I painstakingly aligned and ironed.
Sonny was right on the money. I also keep a razor blade handy to cut , what somtimes turns out to be a bunch of junk off the hook and try again. To me that’s practice.
Not yet, at some tens of thousands of flies and counting. I just do it, and live with the ugly flies.
What he said…hehehe
Some guys take special efforts to type “cripple” flies and some of us do it naturally.
A younger friend with much more time on trout water has convinced me the fish are as particular as the fisherman and they sometime need to see something a little different than what they see every day or weekend. I’m still learning and hope I will still be learning when I hit 90 a couple of decades plus from now.
The amount of time I spend practicing a technique is directly proportional to the amount of heartbreak that could result by failing at it on a real fly.
Example: When I was learning to tie hackle-tip wings for dries, I just went on ahead with it. If they ended up looking ridiculous, I didnt mind, and I’d still fish the fly.
When I started tying parachutes, my first few fell apart almost instantly, so I started tying the hackle off against the post as well as whip-finishing to the post. Since that perpendicular whip finish came at the very end of an involved tie, and had the potential to ruin the fly if botched, I practiced it quite a few times until I was comfortable rotating my whip finish 90 degrees. Now I can do it almost as naturally and neatly as a standard one. The first few times though, it was terrible! Actually stood up and leaned over sideways a few times to get everything oriented.
No, I just “freestyle”.
So Far every woman I’ve been with was happy. 
Is this a trick question? :evil:
If the tecnique is new to me then I will practice just that part until I get it. Then I go to the flies. I cut the sufff off the hook , but it saves me time if it just the part that I am working on.
But then again on most of my flies it probably doesn’t make any difference.
Rick