Polaroid pics

[boxes100]

I am having difficulty understanding how to make shapes truly three dimensional.

I have tried to create a polaroid picture holder/card/thingy (don't know what you call them) but it doesn't look very real. It's still got a flat 2 dimensional look. How do I make it look rounded and 3D?

I'd also like to give it a slightly stippled, cardboardy type fill, but don't yet know how to do that.

All suggestion gratefully received. This is the first time I've posted an image here, please be gentle!

..........Later, how do upload the pic so it appears here instead of just being an attachment? Sorry to be so thick.

Thanks J