I found this =====> http://m.wikihow.com/Stop-Yourself-from-Crying
Of course some of these solutions are not practical during a wedding (watch a movie for example)
I tried #8 at church this past Sunday. It worked. But I found myself concentrating more on not crying that I missed a few moments of the sermon.
I also read somewhere else that looking upwards in general helps. But I think that could look a bit strange (ie what the heck is she looking at). *shurgs* HTH.