Daryl Burling has some good tips for journaling, which is good especially for any who have made a resolution to journal more in 2012.
Don’t be afraid to write personal stuff. If you can’t get out the nasty details about your sin, you probably aren’t going to do a good job of eradicating that sin from your life. We must be willing to be brutally honest with ourselves if we are serious about sanctification. God already knows the ugliness of our sin, so the only person we are surprising is ourselves – which is a humbling thing to do. If you don’t want others to see your personal posts consider password protecting or encrypting your notes.
(Thanks @Challies for the link.)