One of the things I do in friendship craze (my classes to help kids make and keep friends) in the summer is take a popular children's book and correlate it to the games and themes I have in friendship craze. This idea was the seed to my first book.. A.N.T.S. Annoying Nonsense Thoughts. A Guide to Positive Thinking.
Anyway there are a lot of fun ideas, I've used from Harry Potter. Tell the child you are going to learn a transfiguration spell. You are going to change a ANT into a HAWK. Explain a thought that is an ANT (annoying nonsense thought) such as, "I'm bored. There is never anything to do." can be changed into a HAWK (happy, awesome wonderful knowledge). Have the child take the ANT (make a paper ant) and smash it and then say a HAWK and throw a paper hawk into the air. You may make a copy of any ant or hawk.For example they may say to change the ANT into a HAWK, (There are a lot of things to do I just need to figure out some ideas.) Then say the magic spell, "Positive Verto" and throw a paper Hawk into the air. Super fun activity for the kids especially if they are into Harry Potter.
Have them keep practicing until changing their negative thoughts become easier for them.
I am a mother of 3. I have a passion for helping kids feel comfortable in their 'own skin'.