Step 6: Sanding
The best way I have found to sand the inside of these curved shaped is to use a sanding drum in your drill press. This will allow you to remove any saw marks. Sand in steadily higher grits between 100-220.
I used the sanding drum on the inside of the frame and the inside of your cut out drawer. Then hand sanded through the grits until everything was smooth and there were no scratches.
Note: do not skip sanding grits or else you will have to come back and sand the entire box again to remove your scratch marks.
Step 7: Glue Everything Together.
After the insides of your frame and drawer have been sanded, you can glue everything together. Glue and clamp the back to your frame. Then, glue and clamp the front and back onto your drawers. Use some of the scraps saved earlier to glue a drawer pull to the front of your drawer.
I find that using an acid brush to spread the glue evenly will prevent your glue from squeezing out and give you an evenly glued surface. Be sure to sand every surface again before finishing.