Five best practices for working with product designers from Marty Cagan
These five best practices allow the product designer to do the best job possible:
1. If possible, the PM and PD should sit next to each other. If not possible to be physically together, they should work together every day.
2. Include the designer from the inception of every idea. The PM and PD must be partners in creation.
3. Include the product designer in as many customer interactions as possible. The PM and PD should learn about the customer together.
4. Give the designer as much room as possible to come up with design ideas him/herself - fight the urge to provide the designer with design ideas.
5. Encourage the designer to iterate early and often. Don't get critical of design ideas early, allow the end-user to judge usability and value.