When you are viewing a contact profile, the various sections of contact information are listed on the left hand side. By scrolling to the bottom of these sections you will see the button Add sections & fields.
Click Add section & fields to display the Customize Forms screen. Here you can create new sections and fields which can be applied to Prospects or Members. To create a new form/section, click the + New section button at the top left.
Once you have pressed +New section, you will be prompted to enter the Title and fields required. Selecting the Field type will give you the options: text field, checkbox field, date field, number field, currency field, percent field, weight field, drop select field, and user field. Select the fields you require and then enable/disable the switches for Prospects, Members, and whether the field is Required.
Click Save and close and you will be returned to the Customize forms screen. From here you will now see your newly created section on the left column. Drag this section to your Prospects or Members forms to the right.
When dragging the section across, please ensure you have selected the correct title of Prospects or Members as sections are applied separately. Once completed the new section will be available on your customer's profiles.