This part is easy! Here’s a step by step guide to getting your invoice done: Open one of Indy’s Retainer Invoice Templates. Add your business branding and information. Insert your client’s contact information. Number your invoice in a useful way. Fill in the lines with your work completed and the cost per task/hour. Check the invoice total and details. Once you’ve finished these six steps, you are ready to send your invoice to your client. Send it straight from Indy or download it as a PDF and use your own email client to send it.