Series drift is usually blamed on the model. Look at the shelf instead. The character was described from memory at every job, and memory re-shelves her a little differently each time. “Auburn hair in a side braid” in frame one becomes “red elegant hair” by frame four, and the audience watches a stranger take her place. The repair is clerical: file her once, on an archive card you paste rather than retype.
Five fixed lines, always in order
Age — a number, and on this shelf a mature one. Hair — colour, length and one habitual style. Build — two or three words, no more. Face — one or two details that survive any light. Signature — the one object or mark that identifies her at a glance.
Retrieve, do not recall
Pull the card for every job and read the prompt against it before confirming. The thirty seconds that takes is the cheapest insurance in the studio: a frame generated from the filed card can be judged; a frame generated from a recollection can only be hoped about.