I was working a series of part-time and self employed jobs so just put that; "self employed and personal projects". Without any work, I'd put "personal educational projects". If you are skilled, gaps aren't that big a deal anymore, it's not like our grandparents who spent all their time in one or maybe two jobs. I've gotten part-time jobs or volunteered where CV's didn't matter so much and worked from there into full-time too. Another thing, depending on "age"/experience, sometimes you can start your CV later, after all/most of the gaps.

A funny story; my husband interviewed a woman in her late-60's/early-70's, back in the early 1980's and asked about her experience/background and she started with World War II and her War experience (and she was French and had been part of the French Underground, he needed a French transcriber)! He had to gently tell her to start more recent.