1. Go to Settings in the left navigation bar and Select "Subject Type" in the Case Customization section. 

2. Select the Manage Custom Form icon on the right hand side of the subject type you want to customize. 

3. The next section is where you can add, move, and take out information fields for the specific subject you selected. The fields on the left side are the fields you will enter information into when you are adding a case (blue box). You move the field boxes by clicking and dragging them. The fields on the right are available fields you have currently available to add to your subject (red box) (fields can be created). When you hover over the fields on the left you can choose to either: a: remove field from subject (yellow arrow) or edit the field (green arrow). Once you have the fields you want for the subject type finalized you can choose to make any of them a required field when entering a case at the bottom of the screen. 

4. If none of the current fields available apply to your subject type scroll down to the bottom of the screen and select manage custom field and then click "Add Custom Field" in the top right. 

5. In the next window you have to choose from 9 different types of fields (red box) on what you want your custom field to be, once you have selected the field click and hold the type of field and drag it to the left box where the selection will expand (blue box) and you can enter the details for your custom field.