At Katherine's wedding, I cried two times.
The first time was when Daniel and Peter escorted me to my seat.
And the second time was during the Father/Daughter dance.
I was very proud of myself for holding it together otherwise. It was a very emotional day.
So for Daniel's wedding, I've been crying ahead of time so I won't have to cry at the wedding. I imagine things like Heidi walking down the aisle and the look in Daniel's eyes and I tear up. I imagine the Mother/Son dance, and I go ahead and sob now so I won't have to do it later.
I also typed "how to keep yourself from crying" into a Google search for advice. Here are several tips I might try: push your tongue against the roof of your mouth, wiggle your toes to distract yourself, take deep breaths, think of a happy song, or stare at a point out in the distance.
I'll do my best.