I think I would let technology work for me here. Suggest taking a picture of the quilt/picture/drawing, etc. and bring it up in Adobe Photoshop. Adobe has many artistic effects that can be applied to any picture. In fact, I think they have one that is called "mosaic." Another way might be to "pixelate" it where the pic is rendered into the little squares similar to mosaic tiles.
Summarily: Get a picture and play with it in Adobe. Save your best-loved effect and work your fabrics from that.