You probably can add lighting to make it more-pleasant to work there, and adding electrical outlets to make it easier to work there. Painting the interior white will make it look brighter under your lighting, it will be less-drab, and it will encourage you to make use of it.
Often you need to add electrical capacity for the tools which we often use, like stationary 240 volt large-tank air compressors of 15 CFM or > and welders, a 30 or 50 amp 240 volt branch service to a box ready to be wired is a common modification to a traditional attached 2-car garage. Two of those would serve for a welder and an air compressor.
If your branch service panel for the house is in the garage, that would make your re-wire/addition of circuits easier.
Storage space for tools helps you to keep your tools available, makes for an easy inventory, and gets them out of the way, leaving space for working on whatever you do in there. I prefer mobile storage because that provides you with the ability to make space as needed as your needs change, and it eases clean-up.
As-mentioned, the types of work you do are unknown, so you need to provide what you do now, what you want to-do, and possibly a budget. What is your space? Pics help, as-mentioned.