Like most guys, I take my top clothes off first, then bottom. Sometimes I do a mixture like: trousers first, then shirt, then boxers. I think taking your shirt off is not a big deal at all for guys, though when i was changing with a friend at a youth hostel it was the first time he'd seen me topless and he was surprised ;) Later I saw that his chest is quite hairy and mine is naturally very smooth, so i think he was surprised.
Taking my boxers off I always leave until last. I did once wonder what it would be like to take them off first and leave my shirt last before being nude in public, but I think it would look strange!