I want to reiterate before saying anything again that I'm not a copyright lawyer. However, I do know that you cannot copyright a technique or an idea. Paper piecing is a technique. Strip piecing is a technique. Painting on fabric is a technique. Needle-turn applique is a technique. None of these or any other techniques can be copyrighted. If you come up with a cool idea for folding a piece of fabric, that idea cannot be copyrighted. If you make a set of instructions for your idea or technique, those CAN be copyrighted. However, if someone wants to write their own set of instructions to accomplish the same technique, they can do so without infringing on anyone's copyright.
Take the block of the month design featured on the right. Sue Garman has a written set of instructions and drawings that make that block. These include written instructions on certain techniques and also feature the block design. Those are copyrignted. If you write a set of instructions for needle-turn applique or a set of instructions for doing bias strips it would not infringe on her copyright - as long as you don't use her words and phrases. If, however, you are offering the same design, and write your own instructions to make that design, you WILL have infringed on her copyright as that block design is distinctively hers and you would have copied it.
When thinking about copyright issues, remember its the designs or the written words that are protected under copyright laws - not the ideas and methods.