I would just do a combination of listening to them, and burning them in at night. When I 1st got my HD-595, they sounded great, but not as full as I wanted. After about 3 hours of usage, I went to sleep playing music through them all night. I did this for about a month. Using them, and burning them in as I slept with a combination of white/pink noise. After well over 100 hours, the sound expanded, and the bass became much fuller.
I don't understand when people say "don't listen to them until 100+/- hours". How do you know the sound got any better if you weren't listening to them in the first place? Those cans have a great sound from the start as it is (the difference later is not huge, but there), so start burning them in by using them!