I shop at the following places:
Kohl's Department Stores-- there are pretty much no dressing room attendants, so if you want to try stuff on, just grab what you want, and find yourself an open cubicle. I've never been hassled in a Kohl's. I've bought dresses, skirts, blouses, even shoes.
More recently, I've been shopping at Victoria's Secret. The girls there are always nice. It's intimidating at first, but I'm on a first name basis with a couple of the salesgirls at my local. I went in the other day, said I wanted a bra, and without batting an eye, it was "alright, let's get you measured and into a dressing room to try some things on". Easy. No problem. A second girl that was helping me in the dressing room was a little hesitant at first, but by the end of it, she was totally cool. Wrote down the bra styles that I liked and that fitted me best.
I can also recommend Skechers for shoes. Go in the store, grab what you like and ask for it in your size. Assuming your shoe size is 11 or less. I got a great pair of sneakers this past weekend. Tried on like 4 different pairs. No big deal.
The makeup counter at my local Macy's is also great. The Estee Lauder girl is fantastic, helps me out with foundation, all sorts of stuff. Always friendly whenever I'm in the store, even if I'm not buying anything.
I've also got a MAC store nearby for makeup, and the girls in there are always nice. I tell them I want eyeshadow for myself. They ask what color. I say I'm not sure. I'm willing to try a few things. I ask for suggestions, tell them what I wear, and they try and come up with ideas. They'll put a little on, and you can see how it looks. The great part about that is that you're not paying $20 for makeup you'll put on at home, realize it doesn't work for you, and you toss it. In these situations, I think it's important to be honest. By letting the salespeople know that I'm buying this for myself, I can benefit from the advice and experience they have helping out people with similar skin tone/eye color/whatever.
The Body Shop-- salespeople are friendly, willing to let you try lotions, whatever. Their stuff is great, even if it is a little expensive.
Of course, your mileage with certain stores may vary. I'm in southern California, and I doubt that I draw as much attention as I might in a place like rural Arkansas. In the bay area, I'm sure you won't have too much trouble finding friendly places. My only other bit of experiential advice is to consider avoiding population dense areas if you don't think you can pass. I avoid the malls on Friday night because I don't pass. If I go on a Saturday afternoon, no problem. The stores usually aren't as busy, either so I can shop at my own pace.
