Tip #1, Cob Meal: 

Included with your order you may have found a small zip lock of Cob Meal.

Cob Meal is a great product to use under a stone in a bezel setting. It doesn't swell if it gets wet like many things such as sawdust. You can use it to raise the height of a stone instead of trimming the bezel or if you just want a higher profile from your stone. It is also used to level an unevenly cut stone or one that does not have a flat bottom. It's very handy to have on your bench even though you most likely will only use it occassionly. BE CAREFUL not to leave any pieces of cob between stone and bezel or it will leave a bump visible on your bezel when you burnish it down.