From Ambrosia Knight's personal Book of Shadows
You can use an ordinary cup or glass purchased from just about anywhere for your chalice. But a wine glass would be best.
Take your wine glass and wash it. Even though no one drank from it, it was still placed on the shelf by someone you don't know and many others have touched it before you bought it.
Then cleanse it. This is not the same as washing it. This is done to get rid of any negative energies that may still linger in the glass.
To cleanse, fill a bowl with water and add a pinch of kosher salt to it. If you do not have any kosher salt, table salt will do fine.
Place your index finger in the water, stir it three times clockwise, and say:
"As Above and So Below,
I cleanse this water so bad may go.
Please cleanse this ritual chalice for me,
This is my will, So Mote it Be."
Cover the bowl with a clean cloth and leave the bowl undisturbed for one hour. Then, rinse the chalice under spring water. Or, just use tap water. Dry the chalice.
Then, decorate it anyway you choose. You can paint the outside of the glass, but make sure you don't paint all the way to the top where your lips will be. Leave about an inch to an inch and a half of space.
You can also get some fake gems at a store that sells crafts and glue it on your chalice. And / or tie a bow on the base.
Most importantly, be creative! This is your chalice, so add whatever you wish to it.
After you are done, consecrate the chalice. It
is now ready to use.