Add some white glue to a bowl, maybe about 1/2 c. worth to begin with. Stir in 1 tbsp. of liquid Tide laundry detergent at a time stirring in between until it thickens (other brands may not work).
Continue kneading until it is the right consistency. To stiffen it up add a tiny drop of detergent and knead again. Always wash hands after playing with this slime and do not consume.