For the collages I took mostly had and tried to find pictures that were semi similar to each other and work well together side by side, like the two photos that are upside down/tilted go together.
For my portfolio out of the 8 pictures I had 6 of them were from my own theme, the black and white city skylines and then two of my favorite pictures I took this year, one of a sad looking dog in the window and another of kevin posing strangely.