For people like me who enjoy doing a lot of building projects, repairs, and creation, or for anyone who has a hobby that take sup a lot of space, the garage can be the perfect setting to spread out and let your mental energy go. But the problem is that some people's garage doors tend to leak warm air (or cold air, in the summer!) and thus the spaces can eb drafty and ill suited for maintaining a comfortable, livable ambient temperature.
This can interfere with year-round usage, and you definitely don't want to be a 'summer only" DIYer, or a "winter only" painter! Most garage doors only supply a thin sheet of metal (or sometimes wood) between you and the harsh elements- much less than the rest of the walls.
However, there is a solution- garage door insulation kits. They're normally quite easy, affordable, and effective in keeping your garage at a medium temperature. You can get up to five times your previous thermal index performance. Not to mention it can help block distracting outside noises, like garbage trucks going by, airplanes, and that godawful annoying crow in your backyard.
Check to make sure your garage door is a standard size before purchasing, though. Installation should be quick and easy, with the only necessary materials being tape measure, pen, scissors, and maybe some gloves to protect your hands from the adhesive.