I indulge my clothes shopping/decorating jones at Goodwill. My rule is that if I go to Goodwill, I must have at least one small bag of items to donate. It's cheap, it's cash only and when I inevitably get tired of stuff I can drop it right back where I got it for someone else to get tired of. Right now I'm loving my big, flashy faux snakeskin purse.
One caveat- I do spring for new shoes, socks, workout clothes and undergarments. I'm not that cheap, lol.
Agree with ShootingStar, usually just browsing awhile and carrying stuff around is satisfying enough, plus not everything makes it past the dressing room check, cute on the hanger doesn't always mean it's cute on me.