Hi there,
Personally, I have tried different methods and from my personal experience I prefer razors.
I have tried waxing myself and it gives you the smoothest and most long-lasting results but it can be fucking bloody painful it you don't have a good technique. Moreover, that skin is very thin and delicate, and when you pull out the wax you can harm your skin and "peel" it a little and get a scrape for several days (definitely not a good idea having "open wounds" down there when you are having sex)-
I have also tried different electric shavers ( I recently bought Philips One Blade which is supposed to be meant for body and balls shaving) but, in my experience, you have to be very careful and stretch your balls sack very well to avoid bites and wounds. As a result it takes too much time for me.
And finally regular razors, I used Boldking now but I have use Gillete and many others. I have read a pal here saying that he has been said to shave with dry balls and razor, I usually do the opposite, wet warm balls, a clean and not very used blade and plenty of soap or shaving cream. I have never had an accident doing it that way, just make sure to stretch your skin and be gentle but firm.
Remember that if you haven't groomed down there in a long time you should trim off first.
I hope it helped and sorry if my explanations or vocabulary is not too clear ( English is not my first language and it is hard to find the right words to express myself).