I really like to use bean bags for learning to juggle. They don't bounce or roll away when you drop them and you will drop them a great deal when learning. When you become a little more advanced I recommend the juggle balls from BURNINGION at https://www.instructables.com/id/How-to-make-juggling-balls/
they've got great feel and grip when you've mastered the bags. There's also a decent ible on how to juggle from CANNADAKID at https://www.instructables.com/id/how-to-juggle/
check it out. My only suggestion is to sit cross-legged when learning to save on bending over so often to pick up the dropped bags.
Step 1: Materials
The materials needed are the fabric, I chose a sturdy cotton from the remnants bin. I was lucky to find a bright colored fabric with a light texture which will give a great feel for juggling. For a template I used a 3x3 sticky note. A felt-tip pen, scissors, and rice for the fill are the remaining items. I also used a pencil and funnel not shown. The fabric was on sale and I picked up a yard for $2. The bag of rice was an inexpensive variet for $1.20. I estimate I can make about 20 bags with this amount or one set and a couple dinners.
Step 2: Cut Out Fabric
I laid out two sticky notes for the front and back of the bag. For you sticklers for measurements this is 3" x 6". Cut out three of them for each set. Even though felt tip pens tend to run or bleed the line will end up sewn inside the bag and wont show.
Step 3: Sewing
You guys who have never learned to sew should get some lessons. I've never regretted learning. I'm not as adept as my wife, but I can sew a straight line. If your fabric has a front side, fold that to the inside so it will be on the outside of the bag later.
At the beginning of the stitch reverse the machine for 1/4" to keep the thread from unraveling.
At the corner, stop the machine with the needle embedded in the fabric. Lift the foot and turn the fabric 90 degrees to continue the line to the next corner and repeat the process of the corner turn.
At the end leave a gap and reverse the machine again to protect the stitch from unraveling.
Step 4: Reversing Bag
Turning the bag inside out is a neat trick. I insert the eraser end of a pencil and gather the bag up to align the opposite corner with the opening.
Remove the pencil and using the eraser end again push the bag through the opening.
Remove the pencil and pull the bag inside out.
Using the pencil again through the opening you can push the corners all the way square.
Step 5: Filling the Bag
Place the opening of the bag over the end of a funnel. Then fill the bag by putting the rice through. I use the pencil to force the last few grains into the bag. Fill it tightly as it will tend to loosen up later.
Step 6: Hand Stitch Opening
Finally, I hand sew the opening. Fold the fabric of the opening inside the bag. I use a simple whip stitch with double thread. It's not pretty, but I was creating a class set that students would be using and abusing. They tend to disappear and I always have to replace several each year.