Hello @miss3,
Others may define it differently, but I’d say that an Art Witch is any magickal practicioner who incorporates a form of art into their spiritual practice. There are many here in the forum (and jayne has given you some great advice and resources!) - I’d suggest browsing the crafts tag to see what the creatives are crafting 
Additionally, there was an Art Witch Challenge in the forum a while back. You might take a look at the resources there or, if you scroll down to the comments, you can see all of the art magick that the coven did during the challenge. There are some really beautiful pieces!
Blessed be! 