Do Flu-Flu have 3 or 4 feathers. I will be making some for the 1st time.

most of then can have only 4.. but some make them with 6

I make mine with 3. I make em 4.25" long and I get 2 out of one uncut feather.

I make mine two ways, Take a full feather and cut it into 4 or 4 1/2 inch fletchings and use my tool to but on Six fletchings.  But the best way is to take a full feather and do a spiral fletching.  THe spiral stops faster, shoots better but is more noisy.

I'll second the spiral/wrapped feather. A little tricky till ya get it to stay put but stops an arrow fast.

... mike ...

Guru did a "how to" on spiral flu flu's on the How to forum.  i've used it and it was pretty fast & easy.

1 full length spiral.

I use 4-90 fletch on mine.

I like 4

I use 2 - 4" flu-flu to hunt with and 1/2 full lenght, spiral for targets.
My theory is; I want the arrow to reach a squirrel, ground hog, chipmunk quickly, then stop short of normal distance...my thoughts

A Flu-Flu can have as many feathers, or as few as you would like.  Really it depends on what you want the flu-flu arrow to do.  
Our Annual Golf Shoot is coming up here next weekend half the fun of the golf shoot is making arrows.  Got flu-flu's for longer shots and some for shorter shots.

I prefer a single spiral flu flu also. For the shooting I do it's perfect. You can always cut down the profile to increase the distance.
 If you use fletch tape they are very easy to make.  On some primitive flu flus I just wrap the rear, spiral the feather around the shaft and wrap the forward end, no glue or tape used.

I'm sure you've figured it out by now, Glen.  A flu-flu can have whatever you want on it.  A six-fletch stops sooner than a four-fletch (equal sized feathers).  A longer feather stops sooner than a shorter one (holds for both length and height).  Spirals generally stop sooner than traditional fletches.  You can also add about two or three turns of a spiral between the nock and normal 3-fletched arrows.  They all work.  Now you can make up a whole of bunch of flu-flu's and see which you like best!!