i do it with shitty razors because i get them for free...nothign like the feeling of having your ballsack silky smooth. All about just practicing shaving it. Dont press to hard, just go with the grain, tip of the toung, teeth and the toes, your all good
the key is to get em short from the start. I just do everything up with barbers clippers real short anyhow, keeps it nice and cool, then if i'm expecting a lady to spend a lot of time down there I just clean shave the ball sack itself.