Include the source and export formats
STL is common for printing, but STEP can help with review when dimensions, surfaces, or product intent need more context.
Add production notes beside the file
Quantity, material, color, finish, deadline, customer use case, and packing expectations help prevent vague quotes.
Flag known risks before review
Mention thin walls, moving parts, tight fits, cosmetic surfaces, heat exposure, outdoor use, or previous print failures.