Deb Hopper's Just Right Kids Model of Self Regulation is a great visual to teach kids how to describe how they are feeling. Unlike other visuals, Deb divides the concepts of how "busy" our body is vs our emotions, which is easier and more specific for kids to tell you how they feel.
It includes the colours that correlate to other self regulation programs, so it can be overlapped with other learning that may have already been completed. Teach your child or the children you work with how they are feeling and once these building blocks are achieved, move onto strategies for how they can change their behaviour and emotions.
A great tool for the fridge at home for parents and every therapists toolbox!