By Using a Little Barbie Doll Baby Bottle With Water.
It's called method acting. Just make it happen. Think how hard you want to cry for the part. Try crying just for the sake of crying. You used to do it for your parents when you were really young, and pretty much at the drop of a dime. You cried then for nothing. Pretend you are only a year old, and you are really hungry! Try remembering back to when you were a baby, and how you cried then. Think about trying to get your mom to buy you something. Method actors act upon real live feelings, and work them neatly into the part.
Think Of The Saddest Thing That Ever Happened To You, That's What I Do. Deaths Of Close Family Members Or Pets, Usually.
i yawn! when you yawn your eyes tend to tear up! that's what i do when thinking of the saddest thing doesn't work.. you should try it but if you think you didn't tears up enough, try to make yourself yawn a lot.