Two random bits of writing advice

From conversations I had at a party this weekend:

1) After you establish a character in a story, make sure you ask yourself the following two questions before every subsequent appearance of that character:  Where were they since we last saw them?  And what were they doing during their time off-screen?  It's easy to lose track, even with a major character, and pick their thread up right where you left it.  But there's little else that's as jarring to a reader as following one character through ...