Making Crab Shell Ornaments?

It depends on what kind of shells you have as when we was Station on Guam we had what they call hermit crabs and we would paint them red .yellow the color of tulips, stick a stong wire in the bottom after making a small hole, wrape them with florist tape, add leaves put in a pot and u have shell tulips and they are pretty just wish i could send u a photo of them and they last i have had mine since 1975 and they still look good today