Yes, you most certainly can! Either rigid pipe like Sebastian said, or fabric piping.
Pro tip: Put your piping in before you sew the final shape, it's much easier if you aren't trying to work with adding to a shaped form. If you are using rigid, make the channels, if you are sewing in fabric piping, stitch it in. Also keeps you from ending up with it too small because the channels took it in a bit more than expected.
Personally, I'd use fabric piping, it's easier, or, me being me, I'm a dumpster diver type, I'd use plastic strap, it's all over in trash. You also might look at the fabric you are using, see if you can just fold a few layers and stitch them down and add body that way. Look at this thread
1890s Pretty Housemaid Corded Corset - historybounding for modern farmlife for seeing how they add a lot of body, you don't need anywhere near that much, but it's a good example.
All you are trying to do is add a bit of body, and it won't take much to do that.
:D