Navigate to 'Administration' > 'Layout Manager' > 'Custome Layouts'
Click the 'New Report' button at the top-right of the screen. 
This will open the 'Report Wizard'. Here you can set the 'Category' of the report, the 'Display Name' or name of the report and the 'Data Type'.
The 'Data Type' determines which table will be the main table of which the report will pull data from. In the above example I have selected 'Documents' so that my report looks at the 'Documents' table. Clicking 'Finish' will create a new blank report.