Been to Blossom a few times now - first time so that Kate could do my hair and the other times just to shop. I *totally* like the atmosphere there - it's laid back, casual, and most importantly, boutique-ie without the big price tag (actually prices were quite reasonable).
Kate B did my hair and I loved it, she was friendly but not in a 'fake' 'trying-to-make-small-talk-to-pass-the-time' way, and that always works for me. She did exactly what I asked of her.
The other time I was in there it was for a gift.. and I spent a lot of time browsing because they had SO many options.. and since the prices were good, I bought something for myself that I always get compliments on (a green coin purse with a big fabric flower on it). I also like that they have local designers and such, though I wish some of their purses weren't 'made in china'.
If I'm in the downtown Mesa area (which isn't very often), I like to stop by and just browse to see what new stuff they have.