You can extract much of the oils from the lemon by muddling (which is often much faster than zesting), and happens immediately as opposed to waiting for the zest to steep:
- If your lemon has little stickers on it, take 'em off.
- Slice the lemon in half.
- Juice the lemon into the cup **
- Toss the lemon halves into the cup
- Add granulated sugar to the cup (not superfine)
- Add water & ice.
Muddling is basically beating / grinding the stuff in the bottom of the cup. In this case, you're using the sugar to grind the outside of the lemon peel to release the oils. As you're not letting the rind steep into your drink for a long time, you won't get too much of the bitter qualities from this.
** Note that you might want to strain the juice, or you have to sip more carefully to avoid swallowing the pits. Straining is more work up front, and involved cleaning something else, so might not qualify as lazy enough.
I like one lemon to a 16-24 oz glass is about right for me. (if you have cold water and won't need ice, go with the 16oz ... if you're planning on adding lots of ice, use something larger. I use a sugar pourer and don't really know how much sugar I add ... maybe 1TB ?
(and to give proper attribution -- I learned this technique from a stand selling lemonade at the Pennsylvania Rennaisance Faire ... probably 15-20 years ago)