Brake squeal??

I have an 01 Cherokee Sport. I have new 5 month old rotors and pads up front and new 1 month old drums and shoes in back. I put new spring kits on the drums too . I replaced the brakes due to brake squeal. Turns out my pads and shoes were glazed and I needed new drums. Anyway, I still get some squeal from time to time under light breaking from 25 mph to stop. Some people have told me the squeal is from brake dust but I spray brake cleaner once a month. What is causing this squeal and what can I do to stop it? It is quite annoying knowing that I practically have new brakes.

did you buy good pads or the cheapest you could find.
Cheap brakes make noise

I bought the middle priced pads for the front and premium shoes for my rear

Various reasons for squeal. Leaky wheel cylinders, brake fluid on the shoes will make them squeal. Rust will do it, if you let the XJ sit for 2-3 days or longer in a wet climate they coat with rust. New shoes sometimes don't fit the drum exactly, it takes awhile for them to wear in so you're not just braking on half the shoe or less, which can cause squeal. If you use riveted pads or shoes, the rivets can loosen up and/or be loose from the factory. Sometimes it's the composite type on the pad or shoe, high mileage mixes are more likely to squeal. Junk sand or whatever embedded in the pads or shoes can do it also, but most often makes kind of a grinding/sanding noise. Wet shoes tend to squeal, but this usually disappears after they heat up.
Various fixes are to sand the drum and shoe (or disc and pad) cut the glaze off and start over again.
You can sear the pads or shoes with a torch to turn brake fluid into mostly carbon. Temporary fix.
They make a vice held rivet punch with the matching round punch to tighten the rivets up. A brake fabricator uses an electric press/riveter.