Before you create custom fields, you may want to think about field groups. Field groups allow you to organize your custom fields for display purposes. For example, you can have one group called Dues that contains fields related to member dues, and another called Directory Info containing fields that are used in your online directory. The screen shot below demonstrates these examples, along with the default Contact and General groups. (For more information on the screen that this comes from, see Member details page.)
Field groups are purely for organizational purposes; they are not required, and they can be created at any time before or after you create custom fields. By default, all fields you create are added to the General group, and you assign fields to custom groups at any time (see Ordering and grouping fields).
To create or modify field groups, you must navigate to the Manage Field Groups page as follows:
Navigate to Members > Tools and Customization.
In the Member Profile Information section, click on Create and manage field groups.
You will be taken to a screen like the one below. Any field groups you already have are listed.
To create a field group, type the new field group name into the New field group field in the upper right, and click the button as shown below.
The new group will now be ready for you to assign custom fields to. See Ordering and grouping fields for more information.
To rename a field group, click the edit button 
to the
right of it. Then
change the Description field to your liking and click 
.
The field
group will be instantly renamed on all member detail and member edit pages.
You can delete a field group only if it has no fields (individual or
organization) currently assigned to it. Next
to each field group name is a delete button. If
the field group is empty, you'll see a red 
, which means
you can delete the group. If
the group is not empty, you'll see a pale 
, which means
you cannot delete the group. You
can roll over the pale to see how many fields are still
in the group, as shown below.
If the group has one or more fields in it, you cannot delete it unless you remove all the Individual and Organization fields from it on the Ordering and grouping fields page.