The fields of a layout area covers each field and what it does to the form, starting with the name, which is the one thing you cannot change lightly. Validation and default content covers the rules checked on save, set on the input type and on the layout area, and how defaults fill empty areas.
The two organising tools come next and are the least known: Area groups split a long form into sections, and Attributes: settings, not content move settings out of the way, alone or attached to the field they qualify. Finish with A checklist for a well-built layout, and use it in every review.