Here is a card that I used to teach a long time ago. It is done using a quilt ruler and black permanent marker. I call them Marker Grid Cards. Below are the instructions on how these cards are done. They are fast and easy and you can change the looks of them by where you put your grid lines.
The first thing you will want to do is decide what size cardstock you want to work with. I usually work with 5 1/4" x 4" or 5" x 3 3/4". That way I can mat the design when I'm done. Use the ruler and set it on your cardstock so you can mark in 1/4" from the edge of the cardstock. Do that on two oppposite corners and then connect with a line. Finish doing that around the piece of cardstock until you have a blocked outline.
Decide on what images you would like to put in your grid area and stamp one of the images in the outlined area. At this time you can also stamp another image if you have an idea where you want it or you can continue to the next step and then come back and stamp another area.
Using the ruler again; you will draw lines around the stamped images and place them in "grid" boxes. Outline the boxes with stitched marks to make them pop a little. Color your images and decorate as desired. Good luck and I hope some of you get a chance to try this!