You will get the best results if you hold the empty glass at least a foot below the water glass, so that the water gets lots of air bubbles mixed with it. Pour the water back and forth between the two glasses at least 30 times. Cover all three glasses and place them in the refrigerator to cool. Once they are cool, taste each one. The first thing that I found was the the temperature of the water makes a BIG difference.
Cold water is much more pleasing than hot water.
Be sure that all three glasses are the same temperature before you taste them. The tap water should taste just like water, as you would expect. The glass with the dissolved air should taste much more like the tap water. Part of the taste that we like in our water is the result of dissolved gases. I have searched quite a bit and have found that some sources say this is due to dissolved oxygen and others say it is dissolved carbon dioxide with gives the pleasing flavor.