Hey! It may seem as though I am just following a craze but colouring in is quite relaxing and I would recommend it.
You can find free colouring in printables online or colouring in books at anywhere that sells books these days! The are many types available and I would recommend you have a look around at these as well as at stationary to help you with your wonderful creations!
You can try pencils, textas, crayons, watercolour, chalk, paint, the list goes on!
Your artwork can be framed later or used as a card for someone, possibilities are endless!
I have done some great star wars ones, quotes, bible verses and flowers just to name a few!