In a large bowl mix 2 cups Epsom salts and 1 cup baking soda. Dab a few drops of lavender-scented oil onto a 2-x-4-inch scrap of white cotton fabric and stir through mixture. Repeat with drops of food coloring. Continue mixing scented oil and food coloring until desired scent and color is achieved. If desired, make two colors of salts to layer in a purchased apothecary jar (available in thrift shops).
Spread salts mixture onto a cookie sheet for several hours, stirring several times. Wash and dry the jar. Spoon salts mixture into jar.
Tie a baby spoon onto jar with ribbon.
To use, dissolve several teaspoons of salts in bathwater.