Empty out the armoire. Do not leave old clothes in it since the idea is to make this your new place for storing DVDs. This gives it a specific purpose.
Spray furniture cleaner on a rag and wipe down the wood inside and out to remove all dirt and dust. This improves the display and shows pride in your decision.
Arrange the DVDs within the interior of the armoire. Arrange the movies you are most likely to watch in the easiest to get to places while storing the lesser watched movies on the bottom and in the back. If you have enough room, stand your favorite movies up to display them on top of the stacks of the other movies. Open the doors of the armoire show off your collection.