I will take you to the nicest places to take pictures. I know a lot of places others don't go and these places diserve attention to!
You can take as much pictures as you want, there is no rush.
Please don't forget clothes for wet weather or dress up warm in wintery conditions.
It is possible to buy a snack or go inside somewhere to have a hot drink. The drop of point is at the national library at the other side of Daugava river, close to old town. You just need to cross the bridge on foot which is a nice opportunity to take pictures.