Over on Miss Snark's blog there is a extensive debate going on about one vs. two spaces after a period. It always amazes me that writers can be so anal about something that doesn't make or break getting published. It's not as if using two spaces makes you unprofessional. I've had two books and one novella published by a large NY publisher and used two spaces after each and every period.
I wouldn't say I agonize, but I sometimes struggle to convey my character's emotions without telling.
Is there anything you agonize over?