I think 2 Cafe Americanos is the perfect amount.
The first I have with breakfast, which I make on a basic
Krups Espresso maker (which doesn't belong to me, but it's just sitting there on my counter at home). Great way to start the day.
The second I have with snack-time at PinkE. The team takes a mid-morning field trip most days to
Matter of Taste for caffeine and baked goods. Another double Americano later and I'm very focused and only slightly more obnoxious. Their banana & pecan muffins are amazing, but have caused several divorces in recent months.
Anything beyond two double Yankees puts me about 3 seconds into the future. It's weird getting emails before they've been sent.