Jim-
The first key is to get good quality marabou! Dont go and buy your marabou at some chainstore or OE or Sportco.

Go to a good flyshop...you are in Des Moines so a run down to The Morning Hatch in Tacoma or if you make it to Seattle often, a run into Salmon Bay Tackle would be a great investment.

Secondly, I almost always palmer a stiff sadle hackle before I palmer the marabou to give the marabou shoulders and so it stands up in the current. And I always, wet my marabou when I am palmering it...I tie it in by the tip (which is key), make sure the convex side is towards the front of your jig, and then lick your fingers. With your moistened fingers run it along the marabou and pull it back so the hackles are at a 90 degree angle to the plume. With each wrap, pull the marabou back to a 90 degree angle and also lightly pull it back with your dampned fingers to get the flow you want.

Hope this helps...it is much easier done then said.