Purchase Styrofoam balls in desired sizes. Styrofoam comes in a variety of sizes; choose a size that is appropriate for your vase such as 2.5 inches.
Push the tacks in the Styrofoam ball starting from the top. Work your way down the Styrofoam overlapping each previous tack.
Glue the last tack in place by applying glue to the point of the tack and inserting into the Styrofoam ball.
Insert a bamboo stick in a small area of the Styrofoam and place the other end of the bamboo in the sand container. There should be enough sand to support the tack-covered ball
Spray paint the tack covered Styrofoam ball in the desired color with metal paint. Let dry.
Repeat the process to the other Styrofoam balls. Spray paint the same color or add contrast by painting a different color.
Protect the finish by applying a coat of clear varnish.
Place in a vase as filler and set out to add color to a décor.