I'm curious when everyone decides to officially start wearing the next size down. Of jeans, specifically, or just in general. Dress sizes would be much harder for me. I've lost 50 pounds and I haven't gone down a shirt size. I was a 2X before, and I'm still a 2X now, just a little looser. I can fit into some of my 1X shirts, but they are pretty tight still. I always had that problem though. Even when I was another 50 pounds lighter than I am now, I was an XL in shirts. Dresses, I usually had to have them altered to either have more bust or less everywhere else. So that's why I was focusing on jeans size, because it is the one that actually changes for me. But in general is fine too.
I went and bought one pair, on sale, of each size of the jeans I like, so I had goal pants. I try on the next size or two down periodically. For me, I can button my jeans WAY before I"m going to be comfortable actually wearing them. For example, I could first button my size 16s at 237 pounds. I could button my size 14s at 226 pounds. I can almost fasten my 12s. But I'm still wearing my 18s even though I'm clear down to 217. (Note: this is all in the same brand and style of jeans). I think I'm going to switch to my 16s this week because the muffin top is almost completely gone. Everything is loose on them already, except that slight muffin top. Looking over my history, it appears that I generally start wearing a size about 20 pounds after I can first fasten them, because that is when the muffin top is basically gone and they are comfortable to sit down in. I expect that will change as I get into smaller sizes that have less difference between one size and the next (plus the bigger sizes have a lot of stretch to them, my starting pants from 50 pounds ago still stay up without a belt).
I know other people may not have the muffin top problem. Some people have the opposite and have a gap at the waist, but the hips and butt are so tight they can't sit down, or whatever. But in general, When do you all decide to switch sizes when losing weight? As soon as you can squeeze them on? Not until the clothes are comfortable? Not until they are baggy? Not until the next size up is falling off? Do you only switch when you can go down 2 sizes?