Alcohol and soft drinks at a restaurant are marked up because they are easy to pour. Ordering water, or sharing one drink, lowers the bill without cancelling the meal. The same idea applies to the coffee you buy out of habit rather than because you wanted to sit down.
You do not have to quit every treat. Decide which ones you enjoy enough to pay for, and let the automatic ones go. A weekday coffee at 4, five days a week, is about 80 a month. That illustration is not a moral. It is a prompt to notice the repeat purchase.
Start this week
At the next meal out, order water first. If you still want something else after the food arrives, order it then.