If you want to create a custom report template, you can use a GUI based program like Jasper iReport to design the layout and appearance of the template. Jasper iReport is the open source report designer that is available from JasperReports. With Jasper iReport, you can visually design reports without knowledge of the JasperReports library, XML, and Java.
The easiest way to create a custom template is to use the simple template that is available in Metasploit Pro as a starting point. The simple template uses Jasper iReport’s default template and uses a single SQL query to create a table of host machines and a count of the services and vulnerabilities that are available for each host.