I started my day with an espresso and pastry at a local boulangerie... and just sat there until the city came to life... blending in with the crowd. After a few hours of wandering around, it was time for lunch... and I looked for a cafe with a view. My lunches generally consisted of a 3 course meal + a carafe of wine. After lunch, I wandered around for a few more hours until I got thirsty. Depending on the time, I might have dinner #1 (small 1 course meal) while enjoying a glass of wine... or grab some cheese and a bottle... and find a spot with a view. This was usually around 6PM. After dinner #1, I made my way to the Seine to watch the sunset (usually on one of the bridges... each with a different perspective of the city). During summer months, the sun doesn't go down until around 10PM. It makes for some long days. After sunset, I searched out a restaurant for a proper 3 course meal + carafe of wine. My favorite area for dinner was Saint-Germain-des-Prés. It's relatively easy to get a seat if the weather is nice (because of all the outdoor seating)... but it can be difficult if the weather is bad and you don't speak French. I would recommend making a reservation if you think the weather might be bad (if possible, it is helpful to have a french person call to make the reservation that speaks french). Everything is open very late in Paris. Most of my dinners started around 11PM.
These are a few pictures I took of the cafes while wandering around. Keep in mind that the night photos were taken after a day of drinking wine... kind of surprised that some came out decently.