Display the post date.
Respect the date and time format settings unless it’s important to the design. (User settings for date and time format are in Administration Panels > Settings > General).
For output based on the user setting, use the_time( get_option( ‘date_format’ ) ).
Display the author name (if appropriate).
Display post categories and post tags.
Display an “Edit” link for logged-in users with edit permissions.
Display comment list and comment form.
Show navigation links to next and previous post using previous_post_link() and next_post_link().
Author comment should be highlighted differently.
Display gravatars (user avatars) if appropriate.
Support threaded comments.
This file shouldn’t contain function definitions unless in the function_exist() check to avoid redeclaration errors. Ideally all functions should be in functions.php.
Display a list of posts in excerpt or full-length form. Choose one or the other as appropriate.
The search results page show the search term which generated the results. It’s a simple but useful way to remind someone what they just searched for — especially in the case of zero results. Use the_search_query() or get_search_query() (display or return the value, respectively). For example: