The trick is to not overdose, just like any drug. That is the reason I scaled back from about six cups of coffee to about three cups of tea some years ago. If for some reason, I can't get tea, there are no overt jitters or withdrawal symptoms.
The best days start with a nice quiet cup of tea...
Very true. I recently transitioned from 3-4 cups of coffee a day to 1 cup coffee (or black tea) in the morning and 1 cup of black tea in afternoon. It took a week for my body to adjust to the lower caffeine intake but I feel and sleep a heck of a lot better.