In our house, we have a playroom that houses all the kids (for lack of a better word) junk. They still have a few toys in their rooms, but we try and keep most of the toys in the playroom just so they aren't scattered all over the place and have a home of their own to return to at the end of each day.
Aside from toys, my kids love to use crayons, paint, chalk, scissors, tape - anything they can create with. We used to have all of their art supplies in the playroom with the rest of the toys, but that ended up not working very well. Crayons got lost under shelves and tape ended up stuck to the hair of stuffed animals. It was just too much to have in one room. Luckily, we had a little extra space in the corner of the office, which is right next to the playroom.
It has worked out great for the kids. First, it just gives them more space of their own. Second, it keeps all the art supplies in one confined place, which makes it easy for them to find. We have the table pushed against the wall to maximize the space, but we often pull it away from the wall to allow all four of them to sit down at once if they want to.
I also like that we use this space to display art. We have a stainless fridge, so we can't display art there. This provides a great alternative. We either hang it from the re-purposed curtain rod from Ikea or use the oil-pan-turned-magnet-board (which I've decided was the most copied Pinterest project from this past summer). Either way, they get a chance to display their art and it makes the space colorful and cheery for them.
We store all the art supplies for them in built-in shelves that are on the other side of the office. We leave things like crayons, scissors, and tape at their level so that they can access them whenever they want. Art supplies that need adult supervision (paint, glue, etc) we just store on higher shelves. The kids can still see the supplies, they just have to ask to use those that are out of their reach.
Overall, we love this shared art/office space. I like having the art things separate from the other toys and it gives the kids more overall space to call their own. As the kids grow this will probably also serve as a homework/study space, but thankfully we're still a little ways away from that. For now, bring on the art!