I wouldn't really call them gigs so much as happy, paying accidents. Without including too many identifying details, I'll have made over $500 this year teaching a few hours worth of workshops on one of my craft hobbies. My pre-FIRE agricultural labor side gig is part of what made the huge, intimidating FIRE leap feel possible and less frightening: when I realized I was, on a very part-time basis (a few hours per day, only on weekend days), making enough to cover all of our food and utility bills, I thought "Wait a minute..." :-)
I'll have made about $1,000 this year from freelance writing. And, I ended up writing a federal grant for an organization with which I've volunteered (it's an organization related to one of my hobby crafts), and they won the grant, so now I'm getting paid a VERY good hourly rate through June for stuff I was doing for free.