How do you optimise page layouts for usability? What are compact layouts used for?

Page layout optimisation best practices:
— Place the most critical fields in the top-left section (users read top-to-bottom, left-to-right).
— Mark truly required fields as required on the layout; use validation rules for conditional requirements.
— Mark calculated or system-managed fields as read-only on the layout to prevent accidental edits.
— Group related fields in named sections with collapsible option for less frequently used fields.
— Configure related lists: show only relevant related lists; set default columns and sort order.
— Use separate page layouts per record type for different business processes rather than trying to fit all use cases on one layout.
Compact layouts: Define the subset of fields displayed in record highlights panels (the top section of a Lightning record page) and in hover cards when mousing over a lookup field. Also used as the mobile quick view card. Best practice: include the 4–5 most important identifying and status fields. The first field in the compact layout is the display name in lookup links.