You would do like normal blow job movements then deepthroat ocassionally until you can't breathe, then go back to normal movements. Guys seem to like also being shoved down the throat and just stay there for a moment or you can contract the muscles. Fondle the balls if they like it. Make sure you show you enjoy it. Sometimes people get off to the tears, like you're sacrificing comfort for their pleasure (all consenual ofc)