No matter what I do to create a mass of thick tall billowing clouds they always look like they're dirty cotton balls. The results are never realistic or even just good for that matter. Thanks for any tips and/or advice!

take those dirty cotton balls and increase or decrease the density then increase the ambience to lose the color.

http://www.brycetech.com/tutor/bryce/cloud.html that link has bryce clouds (in 3 versions) ready to download and use in scenes. It also shows that the difference in the sky can make a difference in the cloud. If you want a whispy cloudy thats all bright and white, shine the sun on it (means move the white part of the sun control to somewhere between 4 and 8 o'clock) just grab the clouds there and smack 'em in your scene, then change the sky...tada, you have clouds! luck BT

Thanks for the link :) I've been hanging around your site for about the last 4 nights...I think I live there, but haven't gotten to the cloud tutorial yet :)

Thanks guys I'll try both approaches , hopefully I can finally achieve the results that I have been looking for.

I did a pegasus image and just put rock objects in the sky with ambiant cloud texture. One of the tricks is to use the simple white texture and give it transparency, but for your deal, a cloud texture with ambiance is better. Also, don't overlook the sun controls in the sky lab. There are color selections of the light which have an impact on how the clouds look. Remember to pull the little arrow down below the render screen in the skylab and click on 'render in scene'. You'll see the differences the changes make immediately.