I am far from an expert but have found that having a short windon works best for me. Length is one turn around the reel spool and then hangs just at the right casting length off rod tip. I use 120lb supple leader joined with 120lb hollow dacron. I then finish joins off with UV Knot sense which seems a really nice product.

Stelljigger has got it.  Stay away from the premade windons.  They make sooooo much racket going through the eyes and cut a heaps of distance off the cast.  If you are talking about ones that you make with a FG, PR or whatever knot, just experiment.  I have found that I do not like leader on my spool as it increases the chances of windknots around the eyes.  The only drawback is the need for gloves, or very tough fingers.