a lot of guys' balls/taint are left unappreciated. i find lots of guys like having that general area fondled or licked(i suggest only licking the taint when he is shaved, otherwise its like flossing your teeth, and man pubes arent soft liek a woman's)

give him a sensual massage, play with his ears or nipples or play with that 'special spot' he's got on his cock usually rright under the head, with your tongue. its kinda like the man-clit.just playing with that and not actually blowing him will drive him pretty mad.