I've gotten into more mixed media projects this year and have several already planned for the new year. I'm finally using up a lot of my patterned paper that wasn't my style anymore that was just sitting around. I had several 50% off coupons for Michaels and JoAnns recently that went unused. I thought about using them for adhesive but I have a stash of that already and didn't need to add to it. I've been keeping a list of various "needs or wants" that I carry with me. If I go into a particular store looking for something and the store doesn't have it, then I go to my list to see if they have anything on the list. If they don't, then I no longer feel compelled to keep looking for something NOT on the list just to use up the coupon. As I'm doing projects and notice I'm running low on a standard item, then it goes on the list.
I do the same with online stores. I keep a running list of newly released items that catch my attention but I don't get them right away unless I'm absolutely positive I will use it a lot. If I simply like it then it sits on my list. If after several months I still want the item, then it tends to sit on the list a little longer. I may or may not finally end up ordering the item. The items that I tend to end up buying off the stored lists are those that when I go to create a project I go looking in my stash for the item only to realize that I haven't purchased it yet. The process may seem a little "off" or convoluted, but it seems to be working for me. My spending for this past year was way down compared to previous years. I initially thought it was because I simply didn't need anything, but then I realized the number of patterned papers and dies and stamps that I saw that I loved but hadn't actually purchased, so the spending being down was because I had stuck to my new "method".