I am a big fan of social stories to teach young children and/or children with special needs (any age) when there is a problem with a behavior or the child is anxious about a situation. The concept originated by Carol Gray. Although social stories are often used with children with an autism spectrum disorder, I have found that you can use them with many children with developmental delays or young children with no delays. Here is a link on how to make one:
This link probably gives ideas for grade school children, and adapting it for the toddlers would mean doing more of the work. I have had my own children help me by coloring some of the pictures in the book.
I have made quite a few for my own children, and they like to read them even after the issue has been solved. Back when my daughter (now 7 years old) was three years old, she was very scared to go to swim lessons. So, through reading the story to her daily she became less anxious. That is because the predictability of the lessons lessened her anxiety. So often, children act up when they do not know what to expect, and through writing an individualized story about what may happen and what is expected of them, their anxiety may lessen.
Some of the stories that I have taught families to write for their child have included: going to the dentist, airplane rides, gymnastics class, swimming lessons, birthday parties, Christmas day, potty training, the choir singing at church, and the list goes on. Remember, when writing a social story to stay as positive as possible and emphasize the behavior you want from the child and don't say a bunch of "no" and "don't". For example, if the child has a problem with running in the hallways at school you may say in the book "we walk in the hallway quietly and slowly while listening to the teacher" as opposed to "we don't run in the hallway and disobey the teacher".
I would love to hear stories about some of your favorite social stories that you have helped write!