1). Mason Jars–We bought the 24 oz size.
2) 3/8″ neoprene grommet (one per jar)
3). 1/2″ spade bit.
4). Starbucks cold beverage straw or straw of similar width.
At first cut a hole in the middle top of the lid of the mason jar. (as shown in the picture) Always make sure to place the lid on a flat wood surface and do the drill speed slow to medium. This helps it avoiding from puckering and cuts a smooth circle. Then place a grommet in the hole you recently created. The straw then can easily fit through the grommet.
Done! Enjoy you spectacular summer beverages!
***DIY source: http://snapguide.com/