Web: Click Create New > Estimate. Choose blank or template, select the client/property, add line items (from pricebook or custom), apply discounts and tax, set dates, optionally require a deposit, then save or send.
Mobile: Tap + on the Hub > Estimate. Choose blank, template, or new template. Fill in details and save or send.
Templates pre-populate line items and pricing for common services. Select "Use Template" when creating an estimate.