In the very touristic Graça area, there is this heaven place, hidden from tourists. This café belongs to the theater da Garagem. It has an amazing view, the atmosphere is peaceful and with a lot of light. They don't have wifi if you plan to work there though..

Flea Market. Tuesdays and Saturdays.

beautiful collection from a couple of interior designers 

Renovar a Mouraria is a non-profit public benefit organization created to revitalize the Mouraria neighborhood, where more than 50 nationalities coexist, where the fado was born, and where countless Portuguese traditions still manifest themselves in everyday life...

There are not many full of green parks in lisbon, this is a quiet botanical garden that i usually go to read a book and be around dark green plants.