I keep a quilt journal ( on my 4th or 5th one now) that includes sketches or pattern/book/designer information if I used a commercial source. Swatches of the fabrics used, date started, any pertinent notes along the journey, struggles, changes etc. batting choice, backing, materials cost to make it, date finished, if appraised- a copy of the appraisal ; pictures of the quilt, top, back & detail of quilting. if gifted to whom & occasion, if donated to whom & value, if sold, to whom, for how much & date. And, sometimes a copy of the label if its special.