The Designer allows you to add and configure almost all of SharePoint fields including its SharePoint properties. Adding fields is very easy by simply dragging and dropping the onto the form.
The field types that you can add are:
Single line of text
Multiple lines of text
Once the field is added to the layout you can define its SharePoint properties.
Newly added fields:
- have an indicator
- are not created until the user hits the save button
- can have their SharePoint properties changed within the Designer
- are deleted permanently if removed from the layout
Existing (saved) fields:
- have no indicator
- can't have their SharePoint properties changed within the Designer (but they have a link which opens their SharePoint properties in the new tab)
- are not deleted permanently if removed form the layout (removing them simply moves them into the 'Existing Fields' panel on the left side of the page
Adding 'Lookup' field type is a little different then other fields - after placing lookup to the Layout you can decide if this will be a Lookup into the existing list or new. In the second case after hit save both - new Lookup field and new List will be created.