Ice cube tray
Zester (or a cheese grater works too)
Large zip-lock bag(s)
Straw (to help keep some of the acidity off your teeth)
I like to buy a large bag of lemons from Costco and make a large batch all at one time. Wash all of the lemons. Take a couple of lemons to just slice up and freeze (see image). Then, take several lemons, zest them and collect the zest in a bowl. Next, juice those lemons. Pour the juice and zest into the ice cube trays. Freeze. Once they are frozen, pop out and put into a freezer bag or tupperware to keep in the freezer. In the morning (or whenever), place one cube of lemon juice and one slice of lemon in your glass, fill up with water, add a straw - enjoy!