Your question involves any hints or tips on how to handle sneezing because of the pain you are experiencing.
It is generally recommended that you "brace" yourself prior to sneezing, that is, when you know it is going to happen. Bracing involves tightening your abdominal muscles as well as your lower back muscles all at once in order to prevent movement in the spine. It is also suggested to make sure your knees are bent, in order to absorb the shock that may happen down your postural muscle chain.
One of the challenges that you mentioned is that you don't always know that a sneeze is coming. The good news is that with practice, you can engage the bracing method in a split second, just as you get the feeling that the sneeze is just about to happen. That is simply what it is going to take, which is practice at turning those muscles on quickly in order to protect yourself.
Sam Visnic
www.Endyourbackpainnow.com/blog