First, go to Setup, then under Build in the left hand column, click on Schema Builder.
Once the Schema Builder has opened, you will see two tabs (Elements and Objects) in the left hand column of the Schema Builder.
Next, click on the Elements tab, which contains the field type list.
You’ll see all the current fields in the object. To add a new field, just drag and drop the type of field you’d like from the Elements list. In this example we’ll choose “Text”.Once the element is dragged and dropped, a new popup window will appear as shown below:
Fill the object information into the popup window and click Save. The field will get added to the object.
Simply repeat this quick and easy process in order to add multiple fields and save a bunch of time!