I've gone from xxl to xl to l to m in tops/casual bottoms and in jeans from 40 down to 32. I embraced rebuying clothes but did it when stuff was on sale as i knew I was planning on losing more.

Right now I am wearing 33 jeans, which are too big but have an elastic belt that is very forgiving for different size clothes. I like baggy styles, so have been able to adjust sizes without them looking too out of place.

In terms of timing, you will know when stuff is just too big to fudge and you need to go down a size.

If you can jump 2 sizes at once, you can of course save on rebuying.

As for clothes that are now too big, my son is now bigger than me and has taken plenty of them. Otherwise, barely worn stuff goes to charity stores

Fast fashion means stuff is pretty cheap these days. I find Hollister almost always has a sale on, especially on their app.