It's also important to know what type of chunk you should present. Imagine one chunk as a ladder, with very general (or abstract) information at the top and very specific information at the bottom:
Fruit

Apple

Green or Red Apple

Macintosh Apple

Genus Malus
This is also known as the ladder of abstraction. Depending on the situation, you might want to chunk down information (get more specific) or chunk up information (create a broader overview).