The following are all taken from photos of REAL crop circles.

For all of my drawings, the yellow areas are the parts that are mashed down!

Here are some pretty simple crop circles.  Do you see how these could be made if you had two people, some rope and a board to mash the wheat down?

One person would stand in the middle (holding the rope) while the other walked and mashed.  You'd just change the length of the rope to make the different circles.	You'd need to map out the triangle first...  Say you had three people... How would you do it? Would you need four people? Remember that you can't leave any evidence (like holes in the ground)!
This one must have been designed by girl extraterrestrials!	How many circles do you see on  this one?  This crop circle was 300 feet wide!

Here are some crop circles that were made out of hexagons and triangles.  They were pretty easy to make on my art program, but I don't know how the heck you'd make them out in a field in the pitch dark of night!  Can you figure it out?