Scrying is basically
fortune-telling (cliche!!) or
prophesy. Almost everything that is common knowledge *coughcough
hollywoodcoughcough* about scrying is innacurate. Scrying can be done with literally almost anything. It is basically the recognition of patterms in things and inturpreting them. some methods include: (this is by NO means a complete list):
scrying sphere
pendulum
tarot cards
runecasting
i ching
tea-leaves
these are some of the more "traditional" ones. other more unusual ones include:
auspex and related auspices
looking into mirrors
reading omens in animal entrails
wax casting
walnut test
seeing fortunes in skulls
reading futures in spider webs
will add more as i come across them, and at some point if i can find a particular book that is missing at the moment, post the "proper" names for these things, which are odder than the techniques themselves.