I came across this wonderful site called childcareland.com and it has many activities as well as free videos to teach from preschoolers to kindergarteners.
Both my kids know their shapes already, but I just used this activity found on that website to occupy them. It is called: Shapes - Do-A-Dots. I got them to paint the circles with their fingers.
We then did the "Tissue Paper Scrunch and Glue" activity. S didn't want to do it at first. He probably found it too simple. However, after seeing his younger brother doing it, he also decided to try it out himself.
I think this is a creative way to occupy them and develop their fine motor skills.