1) Board member (advisor really) of a crypto/blockchain company. They pay me $5k per month to basically answer questions and help solve certain issues that might arise. There's also regular meetings but all in I spend 4 hours per week max.
2) Small contractor jobs. I was a contractor and home builder in a previous life. These days, I do side jobs both for the extra income and as a way to relax from my regular tech job. I build decks, sheds, small patios, and some indoor remodeling stuff. All of it is really basic because I have no interest in large jobs that would take a lot of time. A 10x12 shed will net me around $6k and I can build it in a weekend. A similar sized deck I'll charge $25k. Small patio pours I'll net $4k. During Christmas season (right now) I also hang lights. I'll charge between $1500 - $2500 and net most of that. Takes me around an hour for a normal two story house.
3) Tech consultant. I help administer various Wordpress and other sites for clients. Basic stuff like plugins, changing font, layouts, etc. Super easy and I get paid a monthly retainer.
4) I work two six-figure engineering jobs. Neither is super difficult which gives me time to do the other things and still have free-time to spend with my family, friends, and hobbies.
5) Rental income. I built a few single family homes and apartment buildings (12 units per building). Nets very good income but can also be demanding because I prefer to do most of the management work myself. Just sold one 12-plex for $1.6MM in August and am sitting on the others.