Geomancy works a lot like the I Ching.  You cast some sort of lot to
get an odd or even number.  For an odd number, you write down one
mark, for an even, two.  This is repeated a few times to yield a
figure.  Geomancy uses four rows of marks vs. the I Ching's three/six.
 I guess that makes them, what, tessarograms?

The original method of casting the lot was to whale away on the ground
with a stick for a while, and then count the number or dots you've
made.  But I just toss four coins: heads=odd, tails=even.

Traditionally, one casts four such tessarograms.  These are called the
'mothers'.  Then by a series of manipulations, these mothers yield
four 'daughters', four 'nieces', two 'witnesses', and a 'judge'.  The
mothers, daughters, and nieces are arranged into a diagram of twelve
houses.  The tenth house corresponds to employment, court cases, and
the weather, the sixth to servants, small animals, illness, etc.

These are the same houses used in astrology; I've also seen tarot
spreads done this way.  But with the geomantic figures, unlike
constellations or tarot cards, it's not only possible to have the
figures repeated, but quite likely.  This adds a bit of a twist.

For instance, say you want to find a lost object.  You cast a chart,
and notice that Tristia is in the fourth house (hidden things), so you
probably aren't gonna get it back.  You also notice that Rubeus is in
the first house (significator) and repeated in the seventh (love).  So
your weed is probably at your ex-girlfriend's place; worse, she's
pissed, and just might narc on you.

Geomancy is a powerful tool.  (And yes, the bitch is going to narc on
you.)

But it's also a bit unwieldy as used traditionally, and much better at
down to earth matters than anything spiritual.

So I played around with some alternate 'spreads' for a while - none
very satisfying - before I decided to follow the I Ching's example and
integrate the lot-casting with bibliomancy.  As it happened, around
the time I was trying to figure out what in hell to do with geomancy,
I was also trying to figure out how in hell to use Liber 963.  They
both have an astrological basis, so BAM!

Liber 963 (The Treasure-House of Images) is a book of rather bizarre
devotional poetry on an astrological scheme by Crowley's friend and
collaborator JFC Fuller.  It's available in print under the wildly
inaccurate title The Pathworkings of Aleister Crowley (in truth,
it's neither pathworking nor by Aleister Crowley), and also in several
places on the web.

Fuller was an interesting guy.  In addition to metaphysical painting
and writing and editing the Equinox, he was also a high-ranking
officer in the British army, a prolific and respected writer on
military strategy, and an early advocate of tank warfare.  Perhaps the
only avowed follower of Crowley who ever 'made it' in the Real World.

The bulk of the book is taken up by twelve chapters dedicated to the
signs of the zodiac, each broken down into thirteen verses for the
signs of the zodiac and for the sun (expressing 'the unity thereof'). 
There are also chapters for the sun and moon (broken down into
thirteen verses which are not attributed astrologically) and the 169
cries of adoration; these three do not concern us here - though I've
been working on something with the cries that I just might post here
later.

For the purpose of this divination, one figure is cast to represent
the querent, and the corresponding zodiacal chapter is chosen; Caput
and Cauda Draconis pose something of a problem here, as they have no
signs attributed to them.  I've taken the semi-cop-out of taking Caput
D. (which signifies new beginnings) to mean 'start over', and Cauda D.
(which means the end of something) to mean 'stop the divination'.

A second figure is cast to represent the querent's HGA, on the basis
of which a verse is selected from the chapter.  Again, there's the
problem with the Draconises, but also with the Sol verse.  So I've
just attributed the Draconises to the sun for this purpose; of course
N and S nodes of the moon != Sol, but I do think beginning and ending
do have something to do with the idea of unity in the Sol verse.

Again, there's the problem that the Leo and Cancer chapters are twice
as likely to be indicated as the other ones, and the same for the Leo,
Cancer, and Sol verses.

But this isn't as big a problem as it appears.  After all, the verse
is to be interpreted in light of the geomantic figures cast.  So the
Leo of Cancer verse resulting from Populus and Fortuna Major is going
to be interpreted rather differently than the same verse resulting
from Fortuna Minor and Via.

The first would suggest stability, harmony, and power; the second
would suggest an unstable state on the verge of change.