One of the ways I’m dealing with lack of art motivation is learning basic calligraphy. I sit down and work for an hour or so daily before I start working on illustrations and paintings.
It’s great to develop hand-eye coordination (each letter style has a particular angle, this one is Roman (I made a mistake looking up the lowercase and called it Bookhand…) ) and relaxing enough to get me into a more prtoductive mood. This part is really important since it encourages me to finish at least one more creative endeavor and pushes the slump away little by little.
If anything, it’s a new skill learned and those are always useful!
If you’re interested in learning, I recommend reading Learn Calligraphy by Margaret Shepherd, since it covers the very basic styles from Roman to Italic.