Prerequisites
The practice project exists, and you can tell editable, resulting, and chain dimensions apart, with the project's unit setting confirmed.
Steps
1.) Understand standard component dimensions. Standard component dimensions are the dimensions displayed by default in a new view frame.
2.) Understand and activate extended component dimensions. Extended component dimensions are displayed temporarily when selecting a component, and can be made permanently visible via Show Extended Component Dimensions in the View Frame tab's selection group — for example, extended pit ladder dimensions (dimension visibility for pit components needs to be on). Before adding your own dimensions, check a component's extended dimensions first — they may already provide what you need.
Result
You know the difference between standard (always shown) and extended (shown on selection, or made permanent) component dimensions, and check extended dimensions before adding custom ones.
Next Step