Measure and cut your twine into 30 inch pieces. You'll need about 12 to 15 strands of twine that are 30 inches each, for each ball ornament.
Blow up your balloon to be approximately 5 inches wide and as round ball shaped as you can get it. Hang your balloon from the kitchen cupboard, the light fixture above your table or from a pipe in the basement. Protect the table/counter/floor below the balloon with newspaper or a drop cloth.
In a disposable bowl, mix 1 part glue with 1 part water with a plastic fork. (Approximately 1/4 cup each of water and glue for each balloon)
Add one strand of twine into the bowl of glue and mix it with the plastic fork until it's completely covered. Find the end of the twine, then run it between the fork tines to remove some excess glue.
Press the end of the twine onto the top of the balloon, then wrap the strand around the balloon all in different directions. When you get to the end of a piece of twine, tuck the end under another piece of twine or press it to the top of another piece of twine so it stays in place.
Continue adding twine to the glue, running it through the fork to remove excess glue and wrapping it around the balloon until you're happy with the way it looks.
Allow the ball to hang and dry for about 24 hours. Again, make sure the floor/table below is protected because the glue will drip as it dries.
When the twine ball is completely dry, detach the twine from the balloon by pushing your finger under the twine or using the end of a fork. You need to make sure ALL of the twine is detached from the balloon otherwise the twine ball shape will collapse when you pop the balloon.
Make a small cut in the balloon, very close to the knot. Once the balloon has deflated, you can pull it out of one of the spaces between the twine.
Cut 6 to 8 inches of twine and tie it to the top of the twine ball ornament so you can hang it on the tree.
Tie some red satin ribbon into a bow and glue it to the top of your twine ball ornament. (Optional).