Theming tips for module developers session by John Albin Walker at DCSF2010

Reuse a theme hook if you can!

links
image
image_style
item_list
username
file_link
html_tag
more_link
pager
progress_bar
table

See full list:
http://api.drupal.org/api/group/themeable/7

Advantages of re-using:

• Avoiding creating your own (addition to) hook_theme(), template or theme function, or template_preprocess_hook
  just: theme('hook', $vars);

John just made sure all of Drupal (i started my own clap, i have to learn to start earlier and keep it going long enough, but some people joined, John thanked us)

• Themers don't have to learn how to theme just your module.
• Instant integration with other modules. He re-used Drupal's core menu theming for menu block module. As a result, DHTML Menu workes with it great!

Theme hook suggestions

Looks for theme_links__node before falling back to theme_links

Awesome!

This gets over the problem of overriding all theme_links or theme_item_list when you really want to do it for one spot.