@Former-Member, possibly depends on why you're buying. It's fun to wear something different? You're not happy with what you've already got? The sheer fun of fossicking for "treasures"?
I know the last one is my biggest drawcard for going into the op shops, but I've gradually become better at looking at my finds and, for the most part, saying "It's nice, but someone else can use it more than me". So I might pick up five things and put back four.
I also consciously decided some time ago that if I looked after the clothes I had and did some home sewing, I could go without buying clothes for a long time, so I rarely buy any now. (And that's mostly because I haven't managed to kick into the home sewing thingy yet.) Younger (Teenaged) Daughter has other ideas, and acquires clothes at an incredible rate.... sigh. I'm not sure what people think about the fact that I constantly turn up in the same few "going out" clothes, but I've really stopped caring. 🙂 I'm comfy with it, if that's not their thing, that's OK.
Aaand the other thing that slows down my buying is the fact that we've got too much of most things, and a houseful of my parents' things still being sifted through. Often I'll look at something nice, but then think "no, I've got more than enough" or "there's probably one at Mum and Dad's place"... So I guess part of it too is being aware of how much "stuff" we already have.
Anne McCaffrey in one of her sci fi novels had people from a future race trying to go through the archaeological remains of our civilisation... and saying in frustration "The Ancients had so many THINGS!" Yep, I'm a fully qualified Ancient, and a descendant of Ancients. Time to set a new paradigm.