Here is step by step how we insulated our shop without using spray foam insulation.

I explain how this method will keep moisture out of our wall cavities on our steel building.
Keep in mind that we live in the North with low humidity and are mostly trying to keep heat in and not out. You may have to take extra precautions when installing your insulation in your garage to make sure to keep moisture out depending on your climate. This is what works for us.