Years ago, when we were young and poor, my wife and I bought a Billy Bookcase from Ikea. It looked like this:
Now that we are sophisticated wealthy adults, we wanted — no, needed — something classier. So, I painted Billy, gave him a face frame, and added moulding to the top and bottom. I made the moulding myself using a roundover bit, a cove bit, and some strategic tablesaw cuts. I also replaced the waxed cardboard that was acting as the back of the bookshelf with some lauan plywood.