Look closely--- those aren't even vases--- they are drinking glasses! You have two options for painting glass like this. You can spray paint the outsides--- like this or paint this insides like this in video. In this particular picture they have painted the inside so that the details around the bottom still show. I love it! You could use glasses, vases, goblets, jars, etc. Cluster them together and fill with flowers.
Hit up your local thrift store, yard sales and boxes in your basement.