The typical sectional door used on your garage means the workspace will be either freezing in winter or stinking hot in summer.
I bought a product called Aircell Retroshield
garage door insulation from Bunnings. A 1350mm wide roll by 6000mm long (8m2) is a bit over $100. You'll need two for your typical double garage door. The insulation material is like an industrial heavy duty bubble wrap sandwiched between two layers of reinforced aluminium foil. It's about 8mm thick. I also bought two cans of aerosol spray contact glue.
I measured and cut the material into panels and then stuck them to the door with contact glue. I wiped down each section first with Acetone. The stuff has stuck like the preverbial to the blanket.
It's made a huge difference. If your ceiling isn't insulated throw some batts in to complete the job.
Anyway thanks for this topic