"I'm struggling with my 6 year old daughter and her clothing. Every morning it's the same scenario.... we try to get dressed, she flings herself and says this or that doesn't feel right. When shopping for her clothes - I try to buy only comfortable items, no wool, no "scratchy" fabric, etc.... We waste a lot of money on her clothing since she will just reject an item and never try it again. I'm getting extremely frustrated and want to stop this early morning craziness!"
All my readers will say to have her pick her outift the night before, including undergarments and shoes, and lay them out so she can get dressed quickly in the morning. And that will be great advice, unless she does that but then refuses to wear them the next morning.
My suggestion is to figure out if there's something she'll wear consistently. Any outfit at all, no matter how boring. If there is, then buy at least 5 of them and have her wear the same thing every day. This will help if there's really something bugging her about other clothes. (And you never know. One friend's daughter wouldn't wear anything with fasteners. Another would only wear pink things.)
If there's nothing she'll always wear, then I wonder if it's a control thing for her, and would try to look at what else is going on in her life that makes her need to control her situation so completely. This could be just a different version of the whole "I'm not eating anything you try to give me" thing that is so common in toddlers. If you can figure out ways to give her more control in other areas, and then establish a consistent pattern for choosing clothes (like having her choose the night before and then stick to that choice the next morning), you might be able to stop the battles.
Good luck. It's not fair--you really shouldn't have to deal with clothing battles until your daughter turns 12.