Report Filter by using a form?

[bluke]

I have a form which is ultimately a filter for various reports, Currently, I have 3 different fields by which to filter the report, start date, end date and region. I need to add more options by which to filter (i.e, employee, department, etc. Here is my issue. How can I make the filter in the report as simple as possible but allowing users to select as many or as few options in the form as needed, some of the options maybe left blank. Help would be greatly appreciated. Thanks