I've used a slate call and mouth diaphrams the last few years. After last season I bought a crystal and really like the sound. You do have to keep it sanded though but when its sanded it really sounds good. The slate sounds fine but if it gets wet its not worth a hoot. I've heard aluminum was good but I can't find any around here. The diaphrams are great for no hands but some people say they either can't make them sound or get gagged with them. I like to use both the scratch calls and the diaphrams. I like the Primos brand of diaphrams. I tried some QuakerBoys and some others but they seemed kind of stiff to me. I take the diaphrams and trim them with scissors to fit my mouth better. You may have to play with them and might ruin a few like I did trying to cut them to the right size. Just start by trimming a little at a time. I cut a few too small. They don't work very good too small. I've never used a box call but some of my friends do and they sound real good but gotta chalk and the slates and diaphrams seem easier to me.