1. Julie/Jaybird Quilts writes on the selvage using a fabric safe pigma pen.
2. Using peel and stick address labels is Rachel/Snippets of Sweetness' method of choice.
photo courtesy Rachel Pascual
3. Leave it to Amy/Diary of a Quilter to think of using a label maker.
4. Lori/a bee in my bonnet creates hand-written fabric labels and safety-pins them on.
5. Rather than actually labeling the fabric, Louise/I'm Feelin' Crafty makes labeled fabric swatches kept on a metal ring.
If you have another system, do share in the comments!