Lay out one straw for each person that will be participating.
Mix one part water and one part dish soap into the shallow container. Stir until the soap is fully dissolved into the water. Mix one part liquid glycerin into the mix as an option to make it extra slippery.
Dip one end of the straw into the soapy mixture until the end is completely covered. Slowly remove the straw to avoid having the small layer of soapy mixture from breaking at the end.
Blow slowly into the end of the straw that you did not dip into the soapy mixture. A bubble should start to form at the end of the straw and expand outward. Continue blowing until either the bubble pops or separates from the straw naturally. If the bubble pops, dip the straw into the soapy mixture again and blow slightly more slowly than you did previously.