I made a post about the blog post the dev made about future games, look for it.
There are hints towards some of the endings. A, C, D, E I think you will easily stumble upon from experimenting since they all happen at the same spot. B is a bit more hidden and by the time you could trigger it, you probably won't be doing the action that does so. So I will spoil it here: Make love with Node when you have level 3 covenant with her, Hatter, Mock Turtle, Wolris, Dodo, Shisha, Bill, Duchess, and Twins. Choose to give up your search for Alice.. F and G you are likely to at least fulfill the conditions for on your second playthrough and there is a hint to what you have to do to actually get on the path to those endings. H is at the end of DLC 3 which you can't even do until you get G end. There should be a file in the game folder called hints.txt that has the ending conditions listed in it.