Single blade razor (single blade safety razor NOT a straight razor unless you want to perform a DIY vasectomy!). Avoids pulling the hair out and cutting it so short it ends up below the skin.
I also find I cannot shave my pubes above the unit without looking like a freshly plucked turkey. Balls and shaft ok, but not above. Weird. Anyway I prefer not to look like a 10 year old so this is a good combo for me.
Bit of exfoliation helps too, powder them up to keep dry afterward as well. Hope this helps.