What a BEAUTIFUL Ball!!!
You can scry with any size ball that you are comfortable with, just like you can scry with ANYTHING you wish to use. (I have some balls the size of a small marble that I can scry with and as large as a baseball) some people use the tile on their floor, the tiles on the walls, and other things that sounds very odd, but they do a great job with it! so, who's to say what is right or wrong. you have to be comfortable with it yourself. I've actually used a blank white index card myself, thanks to Dancingbear here and her help.
First of all, it may take some time to get use to scrying and working with your ball. it's like any other tool, don't expect 100% success w/the first go at it.
hold your ball or gaze into it, which ever is most comfortable for you. that is the key thing--you need to be 100% comfortable, relaxed and at ease.
it is not so much the tool you are using as allowing your mind to relax and give you the messages.
Try gazing into the ball, but it is generally advised in books to spend only a few minutes each day doing so--no more then 10 min. The moment you begin to feel uncomfortable at all or any headache coming on or eyestrain--STOP immediately. other wise you may end up with a doozy of a headache.
After awhile, (could be a long while or it could be the first try--everyone is different), you'll begin to see a cloud like formation perhaps (it is again different for everyone). This can also go on for many days in a row. Then one day, you'll 'see' something in it.
I can remember seeing once a ship in my ball and soon after the husband made an announcement that he wanted to book another cruise.
Don't second guess yourself. Generally the first thing you see as a shape has meaning. The same shape can change itself though to give a second shape, so keep a paper and pen handy to write all down that you notice or feel.
A dream book is very handy to have nearby as you can look up the meaning that way, unless you feel it means something else.
The biggest trick is to trust your own intuition. not always easy to do, so the dream book can help. But learning to trust what you see, feel, hear and smell are key in any form of divination.
the biggest piece of advice is to not give up and also enjoy what you are doing. I have many crystal balls that I have not even divined with yet. some I just enjoy looking at. I'm not that big into crystal ball divining myself. I much prefer tarot or oracle reading, or psychic medium work to the ball or crystals, or tea leaves or what have you. So, if you decide you don't like divining w/a ball, don't worry about it, they are still gorgeous to have near by. The one you pictured is absolutely gorgeous!
Makes me want to finish unpacking all my crystals and crystal balls today and play with them. Enjoy!
oh!, and, there are lots of good books out there on crystal ball reading. Take a look at some and perhaps investing in one or a few will also aide you.