Hey Rich-
It is very easy...find a nice plume that has a thin long stem and nice fibers. Tie it in by the tip and wrap forward (if you are tying the maribou just at the head, wrap each wrap just in front of the previous...if you are palmering a whole body give more room between each wrap...as you are wrapping, pull the fibers back with one hand so you get nice even wraps and so that maribou flows back and doesnt clump. It also helps to wet the maribou and slick it back.

If you want a lighter dressed pattern, strip one side of the plume...if you want a fuller dressed pattern, tie in by the butt and palmer a saddle hackle before you tie in the marbou (provides a base for the maribou).