When we moved into our current apartment almost 9 years ago, my husband used the back room as our studio. It became my studio space when he got a studio outside of our home. I would use it sometimes, but usually preferred working in our living room. When Henry was born and claimed the back room, I officially moved my work table into our living room behind the sofa. I actually love it here and use it so much more now!
This is how it looked before Mike had to move a huge painting to his studio when it was in a show. I miss the painting, but I love having shelf space now. Plus, it was necessary to store all my dangerous and toxic supplies out of reach of a curious 2 year old boy.
I move the sofa when I need to get back there, push it back when I'm done for maximum play space with Henry. We can put drinks back there when we're hanging on the couch which is convenient (especially if your son likes to put his monster trucks in your drinks). 
Our apartment definitely leans toward function. We have a 3 foot closet in the entire space, so built a closet / loft space to the right of my desk. We are lucky to have tons of artwork from close friends, and have hung it on almost every wall space we have. Mike offered to move my 2 giant tack boards I got from work (they're 48"x48") under these shelves, but we were just too tired to do it. One day I'd love to recover them in unbleached linen and maybe some nickel nail-heads, but it's a very low priority.
This set up has been working well for me. When I KonMari'd my art supplies, I only kept what I loved and need. Her idea of using what you already have to display or store your items inspired me to use my white coffee mugs to store my watercolor pencils and colored pencils. I had not used the watercolor pencils in years, but find myself reaching for them a couple of times a week to experiment now. I use them so much more, and they make me smile to see them on the shelf. I got rid of half of my Tria markers from interior design, but am amazed that some of them have lasted over 15 years!
I found myself pulling the same watercolor supplies down each time I'd paint, so designated a red tray I have to house my frequently used items. I have my brushes, inks, Schmincke 12 pan set, and artist's tape on it. I just need to pull it down and put it back on the shelf when I'm done, so Henry doesn't climb back there and eat cadmium or cobalt paint or pour black ink on the sofa.
I had my unused oil paints in a Pantone tin, but wanted something that would hold them better. I decided to put them in a glass bowl we rarely use, and I love it. Since I can't really use them right now with the fumes and baby, I can still look at this bowl of paint and think of what I will make with it later on.
I also moved books that I love for reference and inspiration to this shelf so I can peruse them more easily. I paint on old clipboards (that they were throwing out at work years ago), and store them in a metal magazine rack. I decided to use an extra tack-board we had that was laying unused, and store watercolors in the blue box and wooden box that we used to store mail in.
It was nice to find new uses for things that we had or no longer needed once I KonMari'd other areas of my house (still stalled in the kitchen phase now). Having my art supplies available and out makes me more inclined to use them, and since it's easier to stop and start painting, I find I do it more often.
The best part is that I can still hang out with my son and husband while I do some work, and feel like we're still getting some time in. Or Henry can play while I paint for 5 minutes, crawl on the floor with him for a bit, etc. This is not to say that I don't ever have time to paint alone, in fact I cherish those moments. But I love having options, and a place that is mine in our home.
Here's some work in progress from a typical Saturday. I'll work on a bunch of things since it's usually my big day to get things done. I've learned to embrace the mess, to work fast, and not worry about having everything in order before I can paint.
I think it's so important to have your own space, even if it is just a drawer or shelf in your home that is dedicated to your craft or hobby. It makes you feel good, and I think you are validating yourself as an artist, a crafter, or maker by setting aside space to pursue whatever it is you love. You're saying, this is something I do, and this is my dedicated space for this activity. I'd love Henry to feel ownership over his own space too someday!
I love seeing other people's creative spaces! Do you have your own space? Tell me about it!