I use Dr. Bronner's soap for hand soap. I love it, and I buy it in big bottles that last forever and a day. But Dr. Bronner's doesn't have the viscosity of most hand soaps. It's vegetable-oil-based, and there are no synthetic foaming agents or thickeners. So it runs a little thin compared to other brands of liquid soap, even though it's very concentrated. This creates problems when it comes to using it as hand soap at the sink. I tried putting it in a regular soap dispenser, and it was disastrous. Because the dispenser was designed for thicker liquid soap, the good doctor came shooting out at a pretty high speed and there was soap everywhere. Then I tried putting it in a squeeze bottle, and that just got clogged. Repeatedly.
Finally, I realized that the Internet is full of helpful suggestions. Several message boards recommended putting Dr. Bronner's in a foam bottle. But the foam dispensers I priced out seemed kind of expensive to me. I don't need an $18 soap dispenser that's just going to rust or break, thank you. So I turned to my trusty soapmaking suppliers. Soapmaking suppliers often have an awesome supply of containers and dispensers for reasonable prices.
Wholesale Supplies Plus, a company I ordered from about 10 years ago when I was making my own soap, had a foaming bottle for $4.25 (top and bottom sold separately). I ordered four: one for each bathroom, the kitchen, and one for my face wash.
For the hand wash, I add Dr. Bronner's and a little water. If you're concerned about the water creating a hospitable condition for mold, you could add the natural antimicrobial of your choice. I use Grapefruit Seed Extract, just a few drops is enough. That's it. The soap foam is positively luxurious, and it works so much better to clean. I'm going through soap much more slowly now as well.
The face wash is the best, though. I used to actively seek out foaming cleansers, and I thought that the soap formula was specifically tailored to create foam. But it's not! The trick is in the pump itself, which forces the soap across a fine mesh screen, creating hundreds of tiny bubbles. Any soap will work. This kind of blew my mind. So I loaded up a foaming bottle with my trusty Dessert Essence Thoroughly Clean Face Wash, and poof! Foam.
Super fancy foam that feels so nice on the face and is much, much easier to use. And if one of these bottles breaks somewhere down the line, I can just toss it in the recycling and get another for under $5. But I bet they'll hold up well, because the simpler, cheaper things often do.