A great photo location are all the Miradouros, the view points, all over the city. Due to Lisbon`s geography with plenty of hills there are a lot of them and you can discover the most spectacular ones in my post Miradouros.
Depending on their location they are either perfect for sunset, sunrise or simply during the day or when it is already dark.
This one here was taken at the Miradouro de Graca during sunset. It was quite busy there, so try to arrive early and bring a picnic.
Then there are some more specific locations throughout the city. One I loved was the top end of the Parque Eduards VII, which lays right above the Bairro Alto, the old town of Lisbon. Your view includes the park, the Avenida Liberdade as well as all the way down to the river, as you can see in the photo I`d recommend coming here during the day as then the beauty of the park and the city behind can be seen best.
Right next to here is also a fountain installation with broken walls that can perfectly used in photos as well to vary your poses a little and make sure you don`t have to stand freely in every single picture.
My absolutely most favourite location during our visit in Lisbon is the Fundacao Champalimaud. In case you read my other posts about Lisbon, you already know how grreat this place as well as the water front around it is to take photos during sunset. It lays a little east of the Torre de Belem and tends to be very quiet and thus a real hidden gem for taking relaxed and beautiful photos.
My profile picture is from in the courtyard of the insitution`s building (it is totally free and legal to access the outside parts of the property) and this one here is taken down at the water. The only thing: due to the proximity to the water it does always get a little windy up here. Still, you can use this to play with some scarf of your hair in the wind and give your photos a unique touch.
Additionally, there is the Arco da rua Augusta which has an amazing f´´view over the city on one side and a stunning perspective of the huge Praca do Commercio and the river Tejo on the other one. Up here you can play with the walls and lean against them, put your arms on it, try some funny yoga poses. Simply dare to do some crazy things as well. You`ll see, it`s worth it and your pictures are going to turn out amazing! Definitely make sure you try out all the 4 sides of the rooftop to catch all the wonderful background options this historic arch offers!
Lastly, I want to talk about the Castelo de Sao Jorge which is technically not just one photo spot. In the area there are plenty of locations to take amazing photos. Whether is is on one of the old castle`s towers, inside the gardens, at the edge of the hill or, such as this one, on the roof between some old walls. There are great opportunities all around and honestly, you can spend 3 or even 4 hours in here without being interested in history at all if you want to ;)
At some points you really should bring a bit of patience as due to the popularity of this sight in Lisbon there obviously are a number of tourists and you sometimes need to wait a little until a certain spot is free or there are not people walking in the background of your photo.
There are actually much more great photo spots in Lisbon. This short list simply contains my most favourite ones, all special for a certain reason.
Suggestions for further ones would be the platform around Christo Rei, the Padrao dos Descobrimentos, the Praca dom Pedro V as well as the narrow allleys in Alfama.
Simply be curious and wlak around the city with open eyes to find the locations that fit your style of photography. Have fun taking amazing photos!