This is an example of how the markdown log file produced by my latest version of the Blender Auto Save on RenderAdd-on can be annotated to keep a record of blender file changes and why they were made. Each time a blend file with the add-on enabled is rendered, the add-on saves a image and blend file copy with the same base file name in an auto_saves folder. The add-on also automatically adds the the filename of the blend and image pair, a datestamp, a markdown link to the image file and the render time to the log file.
As I worked on developing a celadon glaze material, I annotated this log file with what I was changing and what I thought of the result. I screen grabbed the node diagram when I changed its layout and added links to my reference image. This very easily gave me the record below of this little project to quickly develop a material for a celadon style glaze.
Reference image
Default material
celadon_glaze_001 {2018-04-13 16:51}
Render time: 0:00:20.183531
Add some color to diffuse
celadon_glaze_002 {2018-04-13 16:57}
Render time: 0:00:20.045838https://github.com/elfnor/blender_auto_save_on_render
Too smooth but highlights are sharper
Roughen diffuse
celadon_glaze_003 {2018-04-13 17:11}
Render time: 0:00:20.356762
Try differnt glossy shader types
Sharp
celadon_glaze_004 {2018-04-13 17:13}
Render time: 0:00:20.082703
Too glossy
Beckmann
celadon_glaze_005 {2018-04-13 17:14}
Render time: 0:00:20.434412
Better but glossy highlight needs to be sharper
Lower glossy roughness
celadon_glaze_006 {2018-04-13 17:17}
Render time: 0:00:20.392772
Better
Make mix use more of diffuse
celadon_glaze_007 {2018-04-13 17:18}
Render time: 0:00:20.221339
Better
Try using Layer Weight for mix factor
celadon_glaze_008 {2018-04-13 17:22}
Render time: 0:00:20.346465
Facing instead of Fresnel
celadon_glaze_009 {2018-04-13 17:24}
Render time: 0:00:20.525302
This is much darker around back edges
Lower Layer Weight Blend value
celadon_glaze_010 {2018-04-13 17:26}
Render time: 0:00:20.299810
Make both glossy and diffuse less rough
celadon_glaze_011 {2018-04-13 17:28}
Render time: 0:00:20.267659
This has sharpened up highlight
Pick the colors off reference image
celadon_glaze_012 {2018-04-13 17:34}
Render time: 0:00:20.231184
Not bad!
Final node setup
Could use a geometry pointedness input node to mix a lighter shade to give the look of a breaking glaze on sharp edges or play with a Voronoi texture for crazing.