Stress balls can be easily made from readily available materials. All you need is a couple of balloons and the right stuff to fill them. If you want your stress ball to feel like a commercial ball, the sewing method can give you the results you are looking for.
Steps
Method 1 of 2: Make a stress balloon

Step 1. Get an uninflated balloon
Do not use water balloons as they are too thin and fragile for this purpose and will burn easily.

Step 2. Choose a filling
For a typical palm-sized stress ball, you will need about ⅔ to 1 cup (160 to 240 ml) of filler. Any of these will do:
- To make a firm stress ball, use flour, baking soda, or cornstarch (a white powder also known as cornmeal) or a soup packet.
- For a softer stress ball, use dried rice or lentils, small beans or peas, or fine sand (available from a hardware store).
- Mix a small amount of dry rice and flour to get something in between. It will also last longer than flour alone.

Step 3. Blow up the balloon a bit (optional)
It won't always be necessary, but it can be helpful if the balloon isn't stretchy enough to accommodate the padding. Inflate it about 3 to 5 inches (7.5 to 12.5 cm) lengthwise, then press down on the neck without tying it.
- It's easier to do it with a clip or have an assistant to keep it closed.
- The filling process can be affected if air escapes while you fill it.

Step 4. Put a funnel on his neck
If you don't have a funnel, scoop the filling into a plastic bottle with a spoon and place the balloon over the neck. A plastic cup smashed on top to form a spout will also do the trick, but it usually makes for a mess.

Step 5. Slowly fill the balloon
If you want to make a typical palm-sized ball, you will need to fill the balloon about 2 to 3 inches (5 to 7.5 cm) deep. Pour the filling slowly so as not to clog the neck of the balloon.
If it gets clogged, use a pencil or the handle of a spoon to clear the opening

Step 6. Take out the excess air and tie the balloon
Remove the balloon from the funnel and let as much air out as you can. Tie the neck of the balloon to close it tightly.
To release the air, pinch near the neck and spread your thumb and forefinger slightly. Leaving an opening that is too wide can scatter the flour everywhere

Step 7. Trim excess rubber
Use a sharp pair of scissors to cut the hanging end of the balloon. Don't try to cut too close to the knot because you could undo it.
Method 2 of 2: Sew a Stress Ball

Step 1. Wrap a small rubber ball in memory foam
You can find the rubber ball at a toy store and the memory foam at fabric stores or specialty online stores. Your memory foam piece should be approximately 3.5 x 5 inches (9 x 12.5 cm) in size and 1 to 3 inches (2.5 to 7.5 cm) thick. A thicker piece will make the ball softer and more squeezable.

Step 2. Sew the foam around the rubber ball
Wrap the foam around the ball and sew it with a needle and thread until it is completely surrounded. Trim excess foam if necessary, to make an irregular spherical shape.

Step 3. Sew a sock or thick piece of fabric around the memory foam
An old sock will give you a durable outer covering, but you can also use a thick fabric. Cut out the sock or fabric to form a tight sphere around the foam. You finished!
Advice
- An easy way to decorate the ball is to use a permanent marker.
- A little cornstarch and a small tablespoon of water will help you make a stress ball that will feel soft if handled gently and firm if squeezed. Let it sit for about 20 minutes before using while the cornstarch moistens.. This type of ball has a shorter lifespan.
- Don't add too much water to the cornstarch or it will become too runny.
- Make sure you don't overfill the balloon.
- Use a clear balloon and fill it with beads.
- Use kinetic sand to make it softer and more fun to play with.
- Do not add floury water to the stress ball, as it will turn into playdough.
- Attach a hairnet to create a cool tightening effect.
Warnings
- Water or salt fillings can weaken the rubber of the balloon and wear the ball down faster.
- Wrap several balloons around the stress ball to add more friction, which will increase the chances that it will break.