Make sure to include a column for each of the following: description of work or services, date worked, quantity, rate, hours worked and subtotal. This makes it easy to tally up the total when you list out multiple projects or tasks you've completed for the client.
Notes: Many people overlook it, but the notes section on the invoice can be invaluable. A simple phrase like "Thank you for your business" will leave a good impression to the customer and increase the chance of an invoice getting paid faster. You can also include Payment Instructions, Warranty Information or even a personalized message in this section to make them feel really special.