I tried making two recipes for homemade toothpaste. I made Homemade Squeezable Toothpaste and DIY Remineralizing Toothpaste. Another option, which I didn't make, was the Homemade Remineralizing Toothpaste. There are a ton of recipes out there, which seem to be variations of Bentonite Clay, Coconut Oil, Peppermint Oil, Baking Soda, and Salt (mostly). I made both and put them in these BPA free tubes.
They are... ok. I keep wanting a bit more zing like I get with Ecodent tooth powder (see this post).
Want to learn more? Read Cure Tooth Decay by Ramiel Nagel. It's fabulous. Ok, he talks about what to eat and to do oil pulling and use a waterpik, but it's a great read (and slightly on-topic).