Clear bottle, colored sand), funnel, cap or cork for bottle, long thin stick that will fit into the bottle.
Bottle must be clean and dry. Using funnel, pour one layer of colored sand. Repeat with a different colour of sand. Use the stick to move sand if needed. Continue until filled completely to the top. Screw on cap or insert cork. A tight fit will keep the sand from moving.
“Create peaks and valleys of color by using the stick to push sand up the sides. Carefully pour the next layer slowly to avoid upsetting the sand you’ve placed on the sides.”