The awesome Shivian has blogged about ritual clothing! http://blog.shivian.com/post/18448462631/ritual-clothing! You should read it and think.
I don't change for every bit of magic and ritual, like, if I'm going out to leave the weekly offering I will take off the dirty apron and take the fresh-baked goods out to the altar in the copse. But for most other stuff I at LEAST put on one of two special scarves. And most of y'all know what the Assembly of the Sacred Wheel ritual outfits look like, tabards and all.