Adding a new form to Queue
Adding a new form to the Queue Kapp is similar to adding a Form to any other. The difference is where the Form is displayed.
Forms used in Queue are in the same forms list as other Kapps.
Most direct method is of course to Clone the form labeled "Basic Queue Item Template".
After cloning and customizing you need to set the Form Type to Task, and set the status to Active.
Now the form is available from the 'New' button from the Queue Kapp console.