There are a lot of scryers here and scrying threads here in divination. We use to do a lot of scrying with each other here and perhaps there is a need to begin again. You can scry with anything, so even if you do not have a crystal ball, you can scry.
Do a search for "Scry" in divination to see what comes up. GotH, SunChariot, and many others in addition to Starry have participated and started threads on this fun divination practice. I have a great book (imho) to recommend on scrying. The Crystal-Ball-Gazing-book by Uma Silbey. I know you can find it on Amazon. But, there are others out there too.
I don't scry much, but have done so in the past. As for what I actually experience, I liken it to reading the cards, though instead of it being a card, I see an image inside the crystal ball. Its not unlike seeing images in the clouds. Did you ever do that as a kid? I still do that too!
And, yes, many people scry with mirrors too. I can't really recall ever doing that. If I did, I didn't do it much....
There are a lot of threads regarding scrying with a mirror too. Some people paint a small mirror black and scry that way too. There are threads with this manner of divining too here.