Measure twice. Source once.
A useful brief begins with clear dimensions, the intended use and the details that cannot change.
Begin with the opening
For a door, record the opening and the existing leaf separately. Note height, width, thickness and the direction it swings. Photograph the hinges and latch as well as the face. A beautiful match in a photograph can still be the wrong fit.
Define where there is room to move
Split the brief into fixed requirements and preferences. The maximum width may be fixed; the paint colour may not be. Include the quantity, intended use, access route and the date the piece is needed. These details make a sourcing conversation much more precise.
Send a simple marked sketch alongside the reference images. Name the files by room or object reference, use one unit throughout, and flag dimensions that still need checking. A short, clear brief is easier to work from than a folder of unexplained inspiration.