The most difficult thing about “all-natural” ingredients for lotions will be the preservative, but they are out there.
I’m not aware of any vegan-only resources, but the Humblebee &Me website is a great learning resource with many vegan recipes.
I also highly recommend purchasing the Lotion Concentrate recipe from DIY Bath & Body (an Etsy shop). This recipe teaches how to make one’s own lotion “base” (she calls it a concentrate but the concept is the same). You then customize that base with your preferred ingredients, to make lotions as thick or thin as you prefer.
All of her recommended lotion ingredients are vegan, except that you must be sure to use a vegan source of stearic acid. It will also be up to you to select organic or “natural” versions of all other ingredients, as well, but that isn’t hard to do.
This recipe is a proven winner among several of us here in SMF. The customizable nature is what sold me initially; the finished lotion quality sealed the deal.
I realize that doesn’t directly answer your request, but it might be wise to start with perfecting one product at a time. The DIY B&B recipe allows you to do that.
Edit: apparently
@Misschief beat me to it - sorry for repeating what she said!