1. Explain the job before the shape
Start with one sentence describing what the part must do. For example: “This cover needs to protect the opening while leaving access to two screws.” Then explain who uses it, where it sits, and what is wrong with the current solution. A reference image can suggest a shape, but it does not explain the requirements behind it.
2. Capture context and detail
Take an overall photo of the assembly, then separate views of the part from the front, side, and back. Show hidden attachment points and any damaged features. Use clear lighting and keep important edges visible. If you annotate a photo, distinguish measurements from rough ideas so the designer knows which information is fixed.
3. Write down the dimensions that matter
Include the overall envelope, hole spacing, opening sizes, and any nearby surfaces that limit the design. State the units. Label measurements against the same features in your photos. Avoid treating an image as an exact scale drawing: perspective and hidden geometry leave gaps that may need a follow-up question.
4. Define what success looks like
Is the first version for a visual presentation, a fit check, or a trial in the actual workflow? Include quantity, preferred date, and any material or appearance preferences. Explain the environment and expected handling. These details help determine what should be reviewed before a quote is prepared.
5. Make uncertainty visible
You do not need to invent missing specifications. Write “unknown” where you need help, and tell us if a measurement is approximate. Share only references you have permission to use. After review, the next step may be a clarification request rather than an immediate model. That is part of turning a useful brief into a useful part.