Here is what you need:
1 cardboard box (I used a box my new sewing machine came in, the dimensions were 7.5"x14"x17"
7/10 yard fabric (for 8 beanbags, less if you want to make the traditional 6 beanbags)
4 cups of uncooked rice
First, I took my box and cut it diagonally on the longest sides, making sure to match up the cuts so they are parallel. This makes the traditional triangle-shaped game board.
Next, I cut the holes through which to throw the beanbags. For this step, I used a Bath and Body Works 3-wick candle and traced it for each hole. If you don't have one handy, just make sure the holes are at least 4 inches in diameter.
For the next step, which is optional, I painted the cardboard portion and I reinforced it with tape. After reinforcing the edges, I used clear contact paper on the top of it to make sure it lasts a little longer without the paint getting messed up. I also had painted numbers next to each hole for optional scorekeeping. I'm not sure if there is some sort of standard for this, so I just made the lowest hole 10 points, the middle hole 20 points, and the highest hole 30 points.
Finally, to make the bean bags, I cut 8 4x8 pieces of scrap flannel fabric. I folded them each in half and sewed up 2 of the 3 open sides. Then, after turning them right-side-out, I filled each one with 1/2 cup of rice. I then folded each end over and sewed it shut for a clean edge that won't fray.
I added a handle to the top of the game board with some yarn and taped it in place on the inside of the game board. This makes it much easier to carry.
I also used one of those cheapo shopping bags to store the bean bags. It isn't a plastic bag, it is one of those reusable ones that you can get all over the place for a buck, but ours was free from the dentist.
Chunk approves of it, and hopefully you and your family will, too!