Do not use cheap glue that has too much water in it.
Mix 1/2 cup water with 1/2 cup glue
In a separate container, mix 1/2 cup water with 2 T Borax (You'll find this
hidden away in a tiny recess of your detergent aisle)
Now, while stirring the Borax mixture constantly, add the glue mixture. It
should immediately glump up and look like blubber (Or at least what we
imagine blubber to look like.) If it isn't really glumpy and tough, mix up
more Borax mixture and add that to it. Use the same toys as with silly
putty. This does not stick to things as much as silly putty.
From Jane Billman