We have an Ikea expedit 4 shelf unit for art and craft stuff, and it lives in the dining room - had to abandon my dream of an uncluttered adult space. 2 drawers with pens, pencils, paint and crayons, rulers etc. 1 shelf with colouring books, blank paper for drawing. 1 plastic box with crafty bits like beads, hama beads, ribbons, glue, loom bands, lolly sticks, stencils, glitter, tissue paper, coloured paper, foil, fabric, scissors etc etc. Underneath 1 plastic box with playdough and cutters etc. 1 shelf for craft kits.
It's a lot, but they do spend most of their time drawing, cutting, sticking, making at the dining room table. I keep things like place mats, and cutlery on top of the unit, so it is handy having it there really.