Start with a clear identity
Use an item name, internal part number and drawing revision. An old purchase order can be a useful reference, but identify any changes since that order.
Mark the dimensions that matter
Highlight fitting dimensions, locating surfaces and the features that control the assembly. Include a datum system when required.
Add material and quantity
State the material grade if already defined. Include order quantity, expected repeat quantities and the number of spare parts.
Agree delivery requirements
List required documents, packing preferences, destination and requested timing. Treat the quotation as the place to resolve open technical and commercial points.