There are lots of opportunities to improve upon this simple design. You could make a fancier base (curve the outside perimeter with a jigsaw, scrolls...
Have a model rocket you, or perhaps your child, is proud of but you don't have a way to display it? Is it propped up awkwardly in a corner, or wedged into an upright position with some stuffed animals? Not all rocket designs stand up well on their own, so here is a simple display stand you can quickly and easily build with basic tools.
Model Rocket to Display
Expended Rocket Motor
1"x6" Pine Board
1/4" Drill Bit
Hot Glue Gun
Sandpaper (~150 grit)
Step 2: Clean the Expended Rocket Motor
Scrape out the inside of the rocket motor to clear any significant residue left over from the burned propellant. You don't have to make it perfectly clean, just remove any large debris stuck to the insides of the motor. Here I used one end of the dowel wrapped in a paper towel to keep the mess down a little bit. Carefully wipe up and dispose of the debris, making sure to wash your hands afterwards (you won't want to accidently get the residue in your eyes or mouth).
Step 3: Drill Out the Nozzle to Accept the Dowel
Enlarge the motor nozzle with the 1/4" drill bit. The nozzle is a hard clay plug with a small hole in it. Take your time so you don't fracture and break out the whole nozzle. If you do break out the nozzle, that's okay you can fill this end with hot glue in a later step. The nozzle simply helps center the dowel and looks a little better intact.