IKEA's basic BILLY bookcase is a versatile square case. It's tall, it's slim, and it comes in a variety of natural wood shades (don't worry about the color, you'll end up painting it anyway). Get two to four units to fill an entire 6- to 8-foot wall. Once you've assembled the shelves, follow this step-by-step guide from A Carrie'd Affair to customize your cornice for an authentic Victorian look. Arched openings mimic the grandeur of Classical Revival-style buildings. If you're confident with your woodworking, you can even incorporate a swan-neck pediment for a look that looks straight out of Kensington Palace.
Next, find the trim you want to add to enliven the façade. Check out WoodUBend products to find trim to place along the cornice. @DIYDanie adds pieces of wood between each unit and installs similar trim to mimic foliated Victorian frames and fluted columns. The Victorian era was all about ornate carved wood, gold leaf, and over-the-top decoration, so don't be afraid to go bold. Once you've attached your trim with wood glue (or the adhesive that came with the product), it's time to paint.