I found some really cool ideas from these places listed below:

Great visual instructions from Fru Billedkunst Blog


Love this example from Becker Middle School

This was a great flyer to use with my students from Kids Artists Blog….Thank you for posting!
I gave my art club the flyers. They took a gander and started to create. These are pretty spiffiy and I love all the colors.
This Op Art Tutorial is AWESOME!
Check it out, 1969