Here are my best thoughts on crying. If you are having a difficult time crying in a performance, then the problem is with your acting technique, not your crying technique. Which is why you are having such a hard time fixing it. You are trying to correct the wrong thing.
Don't try to develop some mechanical technique to make yourself cry. Your character, in the context of the play, isn't using some technique to make him or herself cry. it's the conflict or release of conflict within the character, intentions, etc. that is making the character cry.
If you focus your attention on a mechanical technique, or focus on some imagined, out-of-script sad event, then you are no longer focused on your character. Your mind is not on the character and the circumstances. Your mind is now on the actor trying to cry. Not the character, thinking, remembering, desiring, reacting, feeling the urge to cry, resisting the urge to cry.
Focus on your character and in playing the moment believably. Focus on the through-line, subtext, intentions, timing and all that other acting stuff. I believe there are some Acting Lessons on the AWOL homepage. If you did your job well, the tears will be there when they are supposed to be there. Why? Because if it is believable that the character should cry, and if you are fully absorbed in playing the character, then you will cry.
What if you are not fully absorbed in playing the character? The stage is not so predictable from one performance to the next. Or for camera work, take after take.
What if the tears don't come?
If you are doing your acting job well, then don't sweat the tears. Heck, most members of the audience will swear you actually cried even though you did not. Why? because your belief in the character becomes their reality. That's the magic of acting.
For camera work, (and some groups shoot videos of original short plays) if all acting efforts fail, the closeness of a shot and the level of "realism" required might indicate other measures be taken.
The director simply shoots the scene without your tears, cuts, places some fake tears on your face and shoots the scene again but from another perspective, then edits the two shots together melding the moment just before you were supposed to cry with the moment you began "crying" with the fake tears in place - to make it appear as if you cried real tears. The different perspectives cover for the fakery - just like it does with the other thousands of edits which make up a film. You can cheat a lot in camera work.

I now know that this article was generated in Acting Workshop On Line (AWOL)
Click the link below if you wish to visit that website.