OK, I promised I'd actually post something here once I had enough caffeine to make sense. Since I'm not sure there's enough caffeine in the world to make that happen this morning, I'll post anyway and you can tell me if I've gone off the rails, deal?
I actually came to Tarot specifically due to another writing tool, StoryForge cards.
http://amzn.com/1937002225 I started out just using the spreads that came with that deck. It was when I was hunting among Tarot sites for more spreads that I came across the Moore/Fell Steampunk deck and fell in love. Then I stumbled across this place and lost my wallet. LOL Anyway, this means that I've always looked on my decks as tools for writing. As such, I actually buy most decks based on their artwork with the intent of using them for creation, not for predictive or even introspective reading.
How I use them:
I don't split mine out into Major/Minors/Courts. It's an interesting idea, but a) I hate having to do a really thorough reshuffle to fully randomize decks again for later traditional readings and, b) I'd feel similar to Lareia. For me, that would be too limiting. However, if I were going to do it, I'd probably do that with one deck that I never used for anything else.
I have two main ways I use decks--actual readings/spreads and "character interviews". Readings (usually three cards) & spreads with named positions are used for both character development and plotting purposes. (As with regular readings, I don't use reversals, because again, they're too limiting. Instead, I'll look at an upright card and use the others around to help me determine whether or not to use a reversed meaning.)
A three carder might start with a question like "Give me three plot points to work with" or "Tell me more about [Character Name]". I shuffle thoroughly, keeping either the bits of plot I already know or my mind's eye view of that character, deal out the cards and go from there. Depending on what I get, I may continue to ask questions and toss down three more cards for each, or I may get enough to work with from just one spread. What comes from these tends to be high level, big picture stuff. Typically for this sort of thing, I'll use just one deck.
A spread with positions, such as those I linked earlier, I often approach differently. I'll start by laying out a Story Forge card for each position. While I have a pretty solid rule that I won't swap out Tarot cards for ones I like better, I don't follow that rule with SF cards. With those, if a card doesn't fit the position or overall story, I'll give it some thought, but I won't hesitate to reverse or change it out for another pick. After all the SF cards are laid out, I'll lay the Tarot cards on top of them. (I may also add in an oracle card to each pile, depending on how crazy I want to get, or I may repeat a reading later using an oracle deck.) Once the card piles are complete, I read them
together within the context of the named position. Honestly, forcing myself to do that last bit taught me more about card meanings in context than probably anything else I've done!
Doing this on a 12+ position spread is nuts. It's also incredibly useful. But it's time consuming, especially since you really want to document all of this for use later. My personal favorite spread for fleshing out character motivations is posted and linked in the index. It's big, and it takes a while, but I haven't yet found a better way to get to the amount of information it provides.
Character interviews: I'm one of those writers who has characters that are as real as anyone on the Internet; I can carry on long conversations with them and don't even need a keyboard to do so. Consequently when I'm stuck at any point, or I just don't feel like writing but know I need to, I'll see who wants to talk and pull out a deck for discussion. These talks are usually just one carders, and most characters have a favorite deck. Xavier, for example, is the antagonist in my longest work in progress. Tyldwick reminds him of his childhood home, and we've had an ongoing discussion of that deck that's over 5K words to date. We'll start by looking at the card, and I'll take down observations on it as see through his eyes before asking him a few leading questions. Sometimes, a writing session ends up mostly being a study of that card. Other times, the talk ranges quickly from that card to produce an entire scene that's only loosely related to anything else. Sometimes, a card builds on a previous one and we may run a discussion over several sessions this way. Other times, I may clumsily drop a card and we'll have two to discuss, or a card just isn't doing it for either of us and we'll pick another one. Much of the writing that comes from this ends up being part of the character's backstory, but a more disciplined author might pull back on the reins and push the character into revealing something specific about a given scene with a process like this one.
One other way of working with these isn't one I use for me, but for my husband, who isn't as familiar with the cards. I'll pull out decks that fit his story environment and the Samhain Deck of the Bastard II, which has keywords on the face of each card and looks like a fairly traditional idea of Tarot, which is easiest for him to relate to. I'll shuffle that deck once only at the beginning of this so we don't repeat cards. He'll come up with his question and we'll pull just one card. Typically, he starts talking, could be on the keywords, could be on what he sees. From what he says, I'll then either let him run with it, I'll start talking myself--explaining finer points and nuances of meaning, or sometimes just brainstorming--or, I'll start pulling the same card from other decks to give him further images to work with. Sometimes, what he needs is a Story Forge card to again add another layer of context to work with. Once we've run out of things to say on that card and he's gotten all the notes down, we repeat the process. Sessions like this can run basically until we're both too tired to see straight, but they provide him with so much material to work through, we don't have to do them often.
Speaking of too tired to see straight, the caffeine has run out! Never ask a writer about how to do anything, we can talk forever. Hee hee...! Happy to answer questions if you've made it through this wall of text.