I usually don't plan rides. I'll check the weather forecast, but that's about it.

You are probably going to laugh, but I have an old Garmin eTrex Legend (the old blue one) handheld GPS (but with the bicycle handlebar mount), clipped onto my handlebars. Turn it on and go. I've been in the west end of Richmond, VA since 1996 and know all the streets, side streets, shortcuts, etc... so it's darn near impossible to get lost.