What information should I gather before troubleshooting a New Wash performance issue?

Before advising formula changes, gather this information: How many weeks have you been using New Wash? Which formula - Original, Rich, or Deep Clean? Roughly how many tablespoons per wash? How long and thick is your hair, and what is the texture? How would you describe your scalp - oily, normal, dry, or flaky? Does the issue happen immediately after washing, or develop hours or days later? Do you live in a hard water area? Are you using any other products - styling, treatments, anything that foams? Most issues trace to one of four things: product quantity, rinsing thoroughness, hard water, or formula fit.