What you need is:
2 different fabric prints
and a bucket or paint can or something to toss the bean bags into
Cut out 5" squares. Usually I make 10 or 12 bean bags per game. Once you are done sewing, the bean bags will be about 4".
Using 1/2" seam allowance, stitch 2 squares together (right sides together) leaving about 1 1/2" opening to turn right side out.
Clip the corners. Then turn right side out and use a pencil or knitting needle or paint brush handle (whatever you have) to make the corners nice and pretty.
Once turned right side out, stitch a very small seam allowance around the outside edge (1/8" or less). But don't stitch the opening closed!!
Get a funnel and fill the bag with the plastic pellets. I used about 1/3 cup of plastic pellets. The reason I use plastic pellets is because they can be run the the washing machine and dryer. If you use beans or something else to fill the bags, you might want to let the person know that the bean bags will not be machine washable.
Once the bag is filled with plastic pellets, shake the bean bag to get all the pellets to the 'bottom'. You should have about an inch at the top where the opening is. Put a pin above the pellets and this will help keep the pellets away from the opening while you sew the opening shut.