I keep a journal on my desktop. I was only putting a photo, the size, the type of batting, the date completed and who it was for. However, I have had to repair two of my gifted quilts for great granddaughters and realized that I could have used more information.
With the flannel or fleece backing - would have like to know what type and where I bought it!
With the FMQ thread - would have liked to have known brand and type of thread (cotton or poly)!
The more information, the better IMHO. It does take time but I have referred back to my notes several times.