I just tried this for the first time this month (12/12), and I love it!  I have made some with Bronner's liquid castille soap, and some with liquid coconut oil soap.  Essential oils are optional, but I wouldn't leave them out!  Thieves is a wonderful blend for bathroom hand soap, and Purification works well in the kitchen.  I wash my hands frequently throughout the day, and my hands feel great after using these soaps!

1 cup water
1-2 tablespoons liquid castille soap (I like to mix castille & coconut oil soap)
1 teaspoon vegetable glycerin
10 drops essential oil
foaming hand soap dispenser (I used dispensers we had recently emptied.  I really like the Method foaming hand soap dispenser!)

Pour water, soap, and then essential oils into dispenser.  Shake gently, and enjoy!  (It may take a few pumps to get a good foam at first.)