I believe that making sure your bike is fitted correctly in the first place helps a lot but choice of saddle is the most critical (in my case). I tried a lot of saddles and in the end the one that saved my sausage was the Brooks B17 Imperial below:
Since finding out about it, I have come across two friends who are suffering worse than I ever did both claim they are seeing the doctor because their golf balls swell up when cycling (ouch)!!
I like the look of the Rose Bikes SQlab 600 active saddle
Let me know if you have one!