I really wanted to add some architectural detail to that cheapest of cheap hollow-core door. This image from Patrice Cowan Bevins was my inspiration.
I picked up three lengths of inexpensive shoe moulding from Home Depot,
and six of these shorter mouldings from Michaels (the same bin I got my studded trim from).
This little hand saw has been my best friend today.
I absolutely zipped through the cutting of the moulding using the saw and my miter box (both are about $5 at Home Depot).
The bigger outer square is 20.5" wide and the inner square is 16.5".
I used some Liquid Nails to glue the squares on the door (I very roughly marked out the lines on the door first as a guide), but I think tomorrow I'm going to nail some wire brads in too before I caulk the whole thing and give it a paint job. I'm excited about the yellow! I think it will be a really fun and unexpected.