This tradition started several years back. For two summers in a row, I hired a friend from church who is also an artist and art teacher to come give us private lessons once a week for several weeks. I told her what I wanted and asked what she'd charge. I also knew what I could afford and we made a plan and simply stretched the cost of lessons over as many weeks as I could afford. It was a great investment.
I know many homeschoolers have and do ask me- Why pay for something so simple that could be done for free or for the price of paper and paint? I tell them that I have been homeschooling for a very long time, and for a very long time, I have been learning what does and does not actually work for me.
I knew from experience how unlikely I would be to stay consistent with anything, even painting with water colors, without some sort of formal support. So I paid for those lessons, knowing I'd be forced to make time to watercolor at least once a week if the tutor was coming for that purpose, etc. I looked at it as a strategic investment in something I wanted to value more... And it worked!
Watercolors have become a summer tradition that we never miss now. We watercolor several times a week from May -August. And how that we are more practiced, we can watercolor without the support of an actual tutor. (But we do often like to follow Let's Make Art online tutorials, since the projects are beautiful and fun.)
Is there something like watercoloring that you want to fit into your life and homeschool that you can use your extra time in summer to invest in and learn to do more often?