-You'll want a naked baby, either in his tub or in the sink with some warm water.
-Have 2tbs water and 2tbs baby shampoo mixed in a container-I used an old travel lotion bottle.
-Either cup your hands covered in the solution and blow or use the bubble wands from a bubbles bottle from the dollar store (I recommend the wand)
-Blow bubbles at baby's tummy during bath time and when one pops say "pop!"
-DO NOT aim for the face. This is why I make my own baby-safe solution in case any go in the mouth or eyes the baby shampoo wont irritate like regular bubbles will.
-When the bubbles touch his legs tell him he has bubbles on his legs or arms, etc. This way it's a learning experience too!