Take a sheet of coloured paper and fold it in half width-ways.
Open the paper up and on one half squeeze your paint. If you do this near to the fold this can help ensure that you get one cloud shape at the end rather than two.
Fold the paper closed again and then using your hands rub over the closed paper to spread the paint inside around. Open the paper up to see your cloud shape, you can always add a little more paint or squeeze it around a little more if you need to but try not to squeeze the paint over the edges if possible.
While the paint is drying cut lightning shapes out of yellow paper. Younger children will need a grown up to do this for them while older children can do it themselves.
Glue the lightning shapes onto your cloud and your thundercloud craft is finished and ready to display once it's all dry.