As part of his fundraising for the Clarion Write-a-Thon (to which you can still donate, should the Muse so move you, and the monetary gods be kind), my Clarionmate, Ferrett, has been blogging in-depth on his writing process while he's in the process of writing each story. One of his more recent entries is on what he calls a "hot mess" story. The defining characteristic of such a story for him, is that he has no idea where the story will wind up when he starts it.
He goes on to say what I'm sure are a bunch on important other things about writing (and no, that's not snark. Ferrett is committed to being a better writer, the best he can be, and he's generous in sharing his advice with others.) But I cannot even remember them, because my brain went: OMGWTF! SOMETIMES YOU KNOW HOW THE STORY WINDS UP WHEN YOU START IT?!?
The thing about process is, everyone has one. And everyone's is different. I don't think I've ever known the end of a story before I began writing it, and I don't think I'd be able to write it if I did. Because I write to know what happens next. (This is the reason I don't outline my novels while writing them, which is also why I wind up having to go back and rewrite them. My process, it has its flaws.)
I just finished a short story where I didn't know how it would end until I scrawled the last sentence, and my brain said "ends." When I began the story, all I had in my head was the image of an island made of bones, and three women standing on the shore. It's perhaps the weirdest thing I've ever written, and I'm really proud of it. But I can see where, for a more organized writer than I am, starting with nothing more than an image would be a sign to wait until the thing had developed, not a sign to sit down and start scribbling.
I've said this before, lots of times, but I think it bears repeating: the right way to write is the way that gets words on the page. Look at other writers for ideas, or for advice, particularly if you are stuck, because maybe something new will jar you back into being able to write. But there is no sacred ritual. If there were, I'd be busy performing it, instead of getting ready to go back to my manuscript, and pull out an erroneous subplot.