I noticed a lot of companies (Coates for example) make their charcoal out of willow and I always liked those companies because they're really smooth and dark. A couple of weeks ago the willow tree in my back yard lost a branch so I broke it up into pencil-sized pieces and used TKOR'S paint can method for making charcoal. It was super easy and once everything cooled down I wrapped my favorite ones in painters tape and put the rest in a box! Here's a pic of the ones I used to draw that. I think the different shapes they came out in gave me a cool variety of different tools but I should have straightened some of them out when I was drying the branch.