I don't wear rings these days as my fingers like to swell at random (usually if exercising or if I have any alcohol), but when I did I took them off at the barn. Necklaces too. No dangly earrings or big hoops, just studs or the smallest hoops I can find. I took my eyebrow barbell out earlier this year and am glad it's gone, I hadn't realized how uneasy I was about it at the barn. Nothing on my wrists either, not even a watch.
One thing I see a lot that always bugs me is listening to an ipod while riding. Nevermind the headphone cord, I need to be able to hear what's going on around me. I do however keep my cell in my front pocket when I ride, just in case something happens.
Shoes with a heel (still rocking my 10 year old blundstones and half chaps) and long pants have always been standard to me...always a sports bra and whatever shirt as long as it's relatively close fitting. If it's cold I'll dress in easy-to-remove layers, no pullovers or anything like that.