Functional template is used when the applicant has considerable gaps in his work history. These gaps make a bad impression on employer and hence should be hidden. This format is more focused on the skills rather than the experiences of the applicant.
First of all, you should be able to recognize the essentials of a good invoice template sample. Certain features are common to most small business receipt template. For instance, it has to have the name of the company and its address, as well as the contact information of the customer.