Michaels Crafts sells small decor bottles for about a dollar and some change. They are great for covering with clay. Covering items in clay is easier for me... It's where your imagination can run wild!

Tim Burton Styles

The name of the talented artist escapes me at the moment, and as soon as I find it I will post it. But her Tim Burton style of covering glass with clay are amazing. My rendition of her inspiration pales in comparision.