I found that my previous flinching was more from the noise, not the kick. First of all, make sure you have GOOD earplugs. With proper trigger SQUEEZE the shot should be a "suprise" to you, so the noise may make you jerk when you anticipate the shot.

This might be common sense, but I'm shocked at how many people go to the range without earplugs. I forget 'em one day and flinched the whole time!! Of course, you won't need them for the woods...