It necessarily describes the kind of services offered and the price agreed for providing them. Usually, companies include their logo in the customer invoice template and, depending on the nature of business, they may mention the payment terms and the breakdown of goods or services offered.
Having finally designed the invoice template, you will have to print it. Here, again, you have some options. For one, you may simply customize your invoice template and print the invoice within your office, and submit them to your customer. You may even electronically transmit your invoice, using the email. At times, you may need to provide blank invoices to your servicing staff, enabling them to prepare invoices on the spot and to hand them over to customers for collecting payments. You may also consider having a combination of all these.