1. Click the Elements tab.
2. Click a field and drag it onto an object on the canvas.
3. Enter a Field Label.Salesforce populates Field Name using the field label. This name can contain only underscores and alphanumeric characters, and must be unique in your org. It must begin with a letter, not include spaces, not end with an underscore, and not contain two consecutive underscores.Ensure that the custom field name and label are unique for that object.If a standard and custom field have identical names or labels, the mergefield displays the custom field value.If two custom fields have identical names or labels, the merge field maydisplay an unexpected value.If you create a field label called Email and a standard field labeled Email already exists, the merge field may be unable to distinguish between the fields. Adding a character to the custom field name makes it unique. For example, Email2.
4. If a standard and custom field have identical names or labels, the mergefield displays the custom field value.
5. If two custom fields have identical names or labels, the merge field maydisplay an unexpected value.
6. Enter a Description of the custom field.
7. Enter Help Text to detail the purpose and function of a custom field.
8. Enter a Default Value to automatically insert a value of a custom field when a new record is created.
9. Depending on the custom field type you choose, enter any remaining field attributes.
10. Click Save.