Tip #1: I've discovered something: if I do not go in stores, I do not buy things. I don't consume as much or spend as much. Two very good things - for my home, my mind, and my wallet.
There are many times when stores are unavoidable. But there are other times when stores lure me in - with a sale, with an idea that I'll just go get ONE LITTLE THING - and I come out with a whole bag full. That's how much self-control I have. I can justify many things, especially when I'm shopping solo. Dangerous. Especially when I'm buying things from Mennonite Central Committee thrift stores.
What is it that makes shopping so much fun? It's such a satisfying feeling sometimes to come home with NEW THINGS - or with just something. My mom used to laugh at me because I'd spread out my new possessions on my bed and admire them for a few hours. I still do that.
Why? Is it the pursuit of happiness? That idea that more is better? The hunter-gatherer thing? That little kick, or mini-high you get when you put on new digs? Or see your children in cute clothes? I don't know, but I want to pay more attention to WHY I shop. I'm pretty frugal, but even so, things build up, and I buy way more than what we need. Need is even a funny word in this context. Hardly anything in our house is here because of a real need. It's all wants, piling up boxes and boxes of wants that make me feel good -- until it gets to be too much.
Tip #2: If you MUST go shopping, don't bring your wallet. I've found this is a really effective way to not buy anything. Load up your cart, then have fun putting it all back, knowing that your wallet is safe and so is your home.