Purchase a small shallow box that measures approximately 1 square foot and 2 to 3 inches high. You can build your own box if you prefer.
Fill the box with dry sand from the beach. If you cannot collect the sand yourself, you can obtain ocean sand from most aquarium supply retailers. Keep the sand as flat and even as possible.
Locate decorative rocks that are native to your area. Take a trip to your local park and locate several oddly shaped or fascinating rocks that catch your attention. Clean the rocks thoroughly in fresh water, then place the dried rocks on top of the sand in positions that please you. As a note, you can substitute rocks for seashells if you prefer.
Position a mini bonsai tree in one corner of the garden.
Rake the gravel with a miniature Zen rake to create straight, wavy or otherwise interesting lines around the sand.
Add any small personal belongings of meaning that bring you peace and serenity.