I've dug hundreds of feet of trenches to move around sprinkler and water lines to account for a new patio and fence. Added walls to my home to add an extra bedroom and office. New trim, new solid core doors, etc.
I've painted rooms, ran Ethernet to all the bedrooms, added some outlets, replaced all outlets with tamper resistant ones, and the list goes on and on.
To top it off, I have a project car that I've been working on. They constantly require some small amount of maintenance and something can always be made better. You can be in troubleshooting mode, tracing electrical gremlins, or you can just be mindlessly sanding off rust from the frame.
Once my kids are older, I hope to get them involved somewhat just to teach them some skills. I cherish the memory of my grandfather teaching me some of this stuff and hold on to some things he made for me.
I structure things so that I can have two or so small projects running that I can pick up and set down without fuss, since life and kids often get in the way.
I've definitely saved thousands on some of the work I've done