This advice comes from Ally Carter who is funny and sweet and gracious (and yes, I’m a HUGE fan of her books and I may have acted all giggly the first time I met her!)
Leave gaps–such as open endings and unanswered questions–for your fans to fill in.*
This is great advice because we writers sometimes think we need to put everything on the page. But often (like with W. Hale’s first name) our readers would prefer we leave some things to their imaginations.
*Quote has been paraphrased.