Example 1: when my daughter was 2 she got a fishbone stuck in her mouth. I gave her lots of bread and water so that something would force the small bone to go down. After 5 minutes the issue was resolved and she immediately jumped to her teddy bear and started playing "you have a bone teddy, you need bread, take this, take that". The first plays were urgent and quite serious and the teddy was always "cured" quickly. But later through the following days as she played the same idea she started to improvise. Teddy, in her hands, would cough and cough - I would offer him things for 10 minutes and more and nothing would help him. And she would laugh at this. After these plays fish bones in her mind were no longer serious.
Example 2: when she was 3 we tried to adapt her to a kindergarten. After the first day when she was home she picked up her toy cars and started playing. Some of the cars were teachers, others were children, one was me, another one was her, and one small car was a smaller child that cried all the time. And we played the routine where I came to the kindergarten with her, stayed for a bit, and then went to work. At the moment the "dad" car went to work she would physically tense up and become silent, as if it was really happening. But those moments became easier once she learned more details about what to expect during the typical day in the kindergarten and that later the "dad" car always comes back to take her home. Seems like this experience was helpful as, despite being somewhat shy, she never cried during her adaptation period.