TAROT IN RITUALS! YES!
WAHEY! - at last someone's into 'Portable Magic' and is asking questions about it directly here on AT!
I am Wiccan (Alexandrian initiated - though I'm solitary now if you'd like the detail) and I love props and ritual. Like Nisaba, I have a few props (doubtful that a ritual Athame 1400 years old actually exists - as that word, Athame, is not that old, I think. Other forms of ritual blade maybe. But - I am not a historian, so I cannot make further comment on that here.), and like Nisaba, I do the "entering into the images of the cards" and "hanging of cards on the wall for their energy" amoungst a number of other things. All of which I consider "ritual".
Also - as she says - I doubt there are any recorded "traditional" Tarot rituals in existence. Apart from however the Golden Dawn have and perhaps still do use it (don't know these, as I'm not one of them).
The 1st I saw of Tarot cards being used actively in ritual was in a TV episode of Buffy the Vampire slayer over 10 years ago - where the character Willow (who is the practicing and growing witch of the series) uses it in a spell.
I presently have 3 Tarot decks set aside for ritual/magic:
1) Tarot of the Cat People (by Kyukendall).
I like this deck for use as Donald Tyson describes in his book (or my own variations of it) because the images are (to me) clear and stark, and I like them. They lend themselves easily to my "vision" if you like (I'm a fantasy and sci-fi fan, so Tarot set in alternate realities appeals to me) - and I find them easy to visualise in my minds eye.
I use this deck to "construct" my magic circle including banishing, calling the 4 quarters/elements, and invoking Deities/Entities etc. Then vice versa. Generally the cards are a wonderful visual guide and lend an air of "structure and gravitas" if you like - to my ritual.
I don't use them every time.
The use of Tarot as a tool in ritual, happens according to my mood, just as it does with all the other rituals items that I have.
One week - I might use my Traditional Wiccan pieces, of Wand, Chalice, Pentacle and Athame.
Another week I might use nothing but my imagination.
A third week - I might be away on holiday somewhere and just use props that have come directly out of my immediate environment - say knitting needle, tea cup, side plate and scissor (as opposed to Wand, Chalice, Pentacle and Athame).
And on the fourth week I might using Tarot for the whole thing. So nothing but the cards.
It keeps things interesting and gives a greater colourful variety of props to work with throughout the year, and during the 8 annual pagan festivals that I keep my eye on.
2) Barbara G Walker Tarot.
I've always loved the "Witch-like" imagery of this deck. Infact, it was one of my 1st decks and exploring it whilst reading the companion book by Barbara, was a strong influence on me investigating Wicca many years ago. I.e. it facilitated who and what I am in my spiritual practice today.
I've recently discovered it's great as a visual aid for when I practice my LBRP
(Lesser Banishing Ritual of the Pentagram. A ritual that aims at clearing the space, and the individual of "cluttered" energy; grounding, aligning and strengthening, before the person embarks on magical ritual, or meditation, or even their usual journey into their day. Or for use possibly, if they wish to give their Tarot cards a massive "cleanse" etc. ad infinitum. Ofcourse what one is mostly "cleansing" imo - is the inside of one's brain.)
.
I recently posted this LBRP use here on AT (no replies. Perhaps I should have tried the Thoth section.
) - you'll need to look at the thread entitled "LBRP...and other things" (which is under 'Talking Tarot'. Sorry I'm presently unable to post the link directly to this page - I'm accessing AT via my Facebook page whilst on holiday and... it just gets a bit complicated from there. If the thread doesn't come up, look it up on my profile page under all the posts I've made. It wasn't that long ago.).
I may use either of these decks for imagery that represents other people when I'm in ritual mode - for example if I'm "sending healing thoughts" in their direction.
Y'know - like when one might use a photograph for distance healing (I know this format from Reiki - but it's not the only way people will use the photo of a person to focus on if they're "praying" for them).
I may also use the imagery from these decks as talismans for myself.
E.g. say I've been ill and my immune system appears to be slow recovering - I may choose a card that in some way speaks of swift recovery and strength and use that as imagery to meditate on - with the intension of boosting my immune system.
Or it might be my state of mind which I want to work on getting into a different shape for something particular... etc.
3) Golden Tarot (by Black). Recently just begun using this deck to communicate further with my spirit guides and perhaps at some point even my ancestors (after those recent threads on AT about using the "Tarot for ancestor work". Again - you'll have to search. I do have "spirit guides" but had never thought of communicating with them via cards - and as for my ancestors - well, I explain in the "Tarot for ancestor work" thread my personal reasons for why I'm somewhat reluctant to do ancestor work
).
I also have the Pagan Lenormand which I suspect will become ritual deck no 4) at some point...
I shall discover how in time...
I see earthair may be into chaos magic.
(
and including "dark" comments).
I might modify earth air's comment a bit here:
When people are beginning at the beginning - they do need to be "told" how to do something. Either through reading about how these things are "done": traditionally from grimmoires and the like, or/and in more modern forms, from having for example - the Reiki instructress say "This is the way to do this - using these symbols" - or the colour analyst say "this colour is a more peaceful and appealing colour - repaint your house with it and it's more likely that you'll sell it". etc. etc. etc. (magic is everywhere in many forms). What has to be added to that, is the understanding that the magic is really within the person (back to Nisaba again) - and their BELIEF. And - in the longstanding idea that "traditionally" practiced things (over and over through time) have greater power, simply because so many more people believe in them, that they perhaps develop a "group conscious" energy of their own. Or - that everyone has subconsciously "bought" into the belief.
The basic structure of something, and the roots or protocol, has to learned first (as with all things - in studying of any kind) - before improvisation and personalisation can follow.
Enjoy Donald Tyson's "Portable Magic" !
- make everything bespoke for you and what you're doing. You are an artist working in the medium of magic, using Tarot or other items as your brush/paints.
I'm into experimentation with whatever I'm studying at the time... so yes I probably fall into this category of magician- I only wish chaos magicians would stop writing about meta this and meta that 
I prefer to think of myself as a Womble- making good use of the things that I find 
Plus the Wombles use the M/W symbol from Ace of Cups 