Rings would have 0 weight unless we are talking in bulk. I guess if you want to be anal, a few ounces at best. It would only be a problem if you had hoard, were a jeweler, collector, or noble. Even then, unused rings would usually be in some kind of jewel case or box which would have it's own wieght. Magic rings always worn in my opinion are not worth tracking even with a spreadsheet.
Cloaks would be like jackets or any clothing and carrying lots of clothes get heavy. It is the reason homeless always have to stash dirty clothes as it takes up the most weight in the pack. I would say 1 pound to 5 pounds depending on fabric.
Hats, a few ounces.