Buying a glass foaming hand soap bottle that you can use over and over is a very wise investment.   With foaming soap you only need 1/2 cup of soap to make 2 1/2 cups of the finished hand soap.  A sure way to stretch the soap and your dollar.  Plus you can add your favorite essential oils depending on the season.

DIY Grapefruit Foaming Hand Soap

20 oz glass foaming hand soap pump bottle or recycle a used foaming bottle (see link below)
1/2 cup unscented castile soap or other hand soap refill
2 cups water
2-3 drops olive oil or fractionated coconut oil
20 drops CUREoils Grapefruit essential oil

Fill the glass bottle with the above ingredients.  Adding the olive oil or coconut oil will help moisturize hands and extend the life of your foam pump.