Spirit Walk or Shadow Journey?
A lot of people use these two terms fairly interchangeably, and for most traditions/paths I suspect that is correct. My path however distinguishes between the two, in that the Spirit Walk tends to go "out" where the Shadow Journey tends to go "in." Clear as mud?
So far as I know, there are two typical reasons or approaches to journeying. The first is to journey to discover something that's external to oneself, while the second is to find out something about oneself, or to heal oneself, etc. Now, I know it can be argued that anything we do in this type of vein is internal, but I'm separating the two based on apparent function. Frankly it seems to me that it's irrelevant whether you really "go out" when you, for example, seek information about what is going on with local energy patterns (or whatever else), because it can't be proven either way, and the intent is to find answers external to what is typically considered one's personal boundaries. Therefore it's considered, in my path, external. The rest is interesting to debate, but not really relevant unless you're comparing dreamscapes.
When you are looking for something "external" in my path you are going on a Spirit Walk. The visualization in this case for me is to start by walking into a forest along a dirt path until I get to my grove (my staging area for Spirit Walks, and also the region where I can do my rituals (whatever are required) in "dream" space if I am, for some reason, unable to do them in real space). There I am met by anyone who is accompanying or guiding me on my journey - a helper spirit or any other spirits that are familiar to me. Note that I indicated that I already know any spirit I accompany - unless I am introduced to the spirit by a helper or a trusted "friend" spirit I don't go out with them. That's a simple safety measure, more about it is discussed in my Spirits page. Whether I am accompanied or go alone, I deal with whatever preparations I need to make in the grove (whether I knew about them at the outset or encountered them there), and then venture out on my Walk, if the work in the grove wasn't the entire purpose of my journey.
Journey can also be an effective tool in learning about oneself, and in healing oneself. This is the other common use of the concept of journeying, and it too is a part of my path. This is where you go when you are trying to see what is giving you emotional issues, or when you simply want to learn more about what makes you tick. This is where you can find that mirror inside that so much occult lore says is so horrible to face (no arguments here). This is where you face your darker side, or find bright points you didn't know about. The journey here begins with the classic cave idea - I go into my cave entrance and wander down the passageways until I get to my "me" room. Just like with the grove, there I am met by any spirits which will accompany or guide me on my path, and there I make any relevant preparations. Sometimes the whole purpose of my Journey is to go here and work.
One interesting thing about these two distinct types of work is that often the danger inherent in the spirit walk is understated, which makes the danger inherent in the shadow journey seem almost overstated. Both of these have their dangers, in very different senses. In a spirit walk you often leave what is considered "friendly territory" in your spiritual space, and can encounter some really strange and frightening (or wonderful) characters along the way. You never know who you'll encounter out there. In a shadow journey you often travel directly into your own dark side - the only thing you have to fear is yourself. You'd be surprised just how scary you can be, particularly if you happen to stumble over something traumatic that happened and you had forgotten about. Perhaps this trauma is the key to what you were looking for - but you've got to acknowledge at the outset that there probably was a reason you hid these things from yourself, and you've got to be prepared for the consequences of your acts. While I won't say "don't try this at home kids," I will definitely suggest that if you are inexperienced at this type of work, and you do decide to start either one of these kinds of quests, you may want to make sure you're not alone in the house. From the spirit walk you could return quite "weirded out" and jumpy, or unwittingly bring a tagalong back with you, while with the shadow journey you could step into a childhood trauma and need someone to pull you out.
Since the shadows (shadow journey) and the light (spirit walk) are both distinctly part of my path, I make the distinction between the two and use them both as needed for my purposes. They're not mental toys however, and both must be treated with respect. Nothing is free of consequences.