I do the vast majority of the work on our vehicles. I'm not a mechanic but have been tinkering with cars since before I could drive and have amassed a good anmount of tools and experience along the way. I started out mostly out of necessity and not being able to afford to pay someone eles to do work (started a family young as a junior enlistedman in the Army, so money was very tight). That gave me a good foundation and once I got into performance stuff about 15 years ago, it just made more sense to do it myslef as that was a big part of the fun.
I am fortunate that I have a good network of friends, several of which are professional mechanics, and /or have been in the auto racing hobby for decades. I have done normal maintenance, repairs to fuel systems, full tune-ups, lift kits, lighting, chased down vacuum leaks, and even a complete engine swap on my sons old 2002 Mustang GT over a weekend!
I am still a little green once you crack open the internals, but as I said, I always have friends available to help.