How Do You Supplement Your Income?

NYC-based. This is my 6th year full-time private tutoring, and I'm doing pretty alright for myself income-wise. Exploring other work options as a way to supplement my earnings and wanted to ask what other jobs part or full-time tutors have taken on. Any ways you've been able to transfer your skills elsewhere? I'm mostly interested in taking on extra work in the summer when clients start to wane, so I'm trying to get on top of that now.