There are, roughly speaking, two kinds of spiritual journey. One is travelling through other places - Faerie, the Nine Worlds, that kind of thing. That is a useful skill to have, and can be a wonderful or terrible experience in its own right, but it's not what I've had on my mind lately.
The other kind of journey is more internal. That's not to say it isn't real; the inside of your head can be a very dangerous place, and your self is absolutely real. It isn't taking you elsewhere, though. The beings you interact with there are often archetypes - spirit animals, guides, parts of yourself, and sometimes deities. You go somewhere inside yourself, and you learn something if you're lucky, and then you return.
I have experimented with using the writing process to guide this type of journey. When I am in the right mindset as an author, writing fiction is a bit like automatic writing. I feel as if I have very little control over the way the story is going, and I share in the emotions of my main characters. This makes it possible to "write" a journey that has at least as much emotional space and room for surprise as a guided meditation.
Because it is meant to be a practice heavy with archetypes, I found that using fan fiction can make the process a lot easier. If TV Tropes has taught us anything, it's that media is just filled to the brim with archetypes (which is just a nice way of saying cliches, sometimes) and the themes of myth are being reenacted right now on network television. If Once Upon a Time or the Vampire Diaries or, hell, Hannibal or White Collar gives you the framework you need to hang your internal work on, I say go for it.
The trick is in being able to reach that mindset where you're honestly experiencing the emotions of the main character you're writing, making choices as a person in the experience instead of from authorial fiat. Once you can step that far in, writing can be done in a light trance (again, not unlike automatic writing) and the journey may begin to surprise you.