I feel like to non-witches the crystal ball is the definite face of fortune telling/divination and they are sold on the SoM site but I have yet to see them discussed or even mentioned by a bonafide witch.
I am very interested in divination as it is a large part of my craft so I'd be curious to know if anyone has any information on how crystal balls are used, if they can be used as a standalone divination method or as supplement to another method, etc. Anything you know would be helpful!
I have a selenite orb and stand I got as a birthday gift years and years ago, but I just use it as you would use selenite normally, and I'm unsure if there's anything crystal ball-specific I could get up to with it.
Crystal balls are used [almost] exclusively for scrying. The same can be done with a bowl of water, or as John Dee famously used (as well as is used in Goetic works' Triangle of Art), a black mirror -- whether a pane of glass with the back painted black or using a polished obsidian.
There are a lot of different methods, some more formal than others in their descriptions -- such as claiming that scrying can only be done by candle light, with a specific number of candles placed in specific locations relative to the scrying device and the one gazing. But some people practice scrying with their phone screens on the bus, so take everything with a grain of salt. I think an environment with controlled lighting may be a place to start as it helps redulce distractions from the practice at hand.
But still, there are loads of resources online, and it boils down to basically this:
Scry with a question in mind.
Gaze either into, as if through, the gazing object, or near it. Different people have different preferences.
Relax your eyes, and don't "try" to see.
Many people experience a fogging over of the vision, and this typically precedes the visions while scrying.
People's experiences vary. Some people see more abstract shapes, and interpret those. Some people have full-on visions with audio of the scenes within. Your mileage may vary.
A journal may be a good idea, to help establish to your subconscious that what you are doing is important, as well as keeping track of questions and answers.
I use a small crystal ball for divination with some success. Prsona made some excellent comments about how to use one and what one can expect. For me I prefer to work in a darkened room with a candle or a few candles for light. I tend to see things symbolically rather than actual scenes of something occurring.
You asked a second question as to whether one can use a crystal ball as a standalone form of divination or in conjunction with a second one. I would say absolutely yesto both. As an example, if you were scrying with the crystal ball and you were uncertain as to what the meaning was of what you saw, you could always turn to a second form of divination to clarify the situation.
Sorry for responding late. I actually forgot I posted this, oops.
This is very good information and I'll definitely look into it further. I have a purple chime candle which I bought specifically to use while divining that I think would be perfect to try this. I also think sitting in a dark room by candle light is very relaxing.
As for the many resources Prsona mentioned I'll be reading around. Thanks for helping me get started!