Tartini's Art of Bowing, 50 variations on a theme by Corelli for solo violin, is a really wonderful violin workout. The variations are so much fun to play that it is easy to forget that they are actually good for you. And our kind friends at the Werner Icking Music Archive have a beautiful edition for anyone to download as a PDF. There is a version for violin (the original), and there are also versions for viola, and cello.
The picture here is not about the Art of Bowing, but it is about Tartini's Devil's Trill sonata, which came to him in a dream.