Repeat the same views — Clinical hair-photography guidance emphasizes consistent, standardized views so serial images are easier to compare.
Keep preparation consistent — Try to keep parting, hair state, distance, camera position and lighting similar. Note when conditions differ rather than hiding the difference.
Record the real context — Write down the date, products or treatments used and important routine changes. A photo documents appearance; it does not isolate causation.
Do not turn documentation into a promise — Before-and-after imagery can imply an efficacy claim. Public use needs clear context, appropriate support and separate permission from the person photographed.