Surface Area and Volume

This is the time of the year in Geometry for teaching about surface area and volume. Helping the students understand how to find surface area and volume is too difficult. They can visualize where the areas are and what to do to find an answer with or without the formula. The problem I have is finding quality practice problems that challenge the students beyond finding the surface area and volume. The students are rarely asked to just find the surface and volume and these types of problems are difficult to make up. Does anyone know where I can go online to find some of these problems? I would really appreciate any ideas.