I am just starting to look at sweaters and hoodies for Lady now that it is getting cooler. She has never worn clothes either. I had a little cheerleader dress on her for a game this weekend. She really got frustrated with it after an hour or so. I think, like anything, they have to get used to it. We might have more of a problem since our pups are adults. I think a good fit is key to their comfort. The cheerleader dress is a bit to big for Lady. I would invest in a tape measure so you can get a good idea of length, girth, neck, etc. Most clothing is sized that way. I would hesitate buying a generic small, medium etc where measurements aren't given unless you have a clothing piece that fits him to directly compare it to. Chihuahuas have a weird little body with a big girth (broad in the front) narrowing to the waist. This is why the cheerleader dress fits Lady odd near the back legs. You will probably have a better fit if buying something where neck, girth and length are provided.