I used my iPad to create the drawings, just using the sketch app with the ruler to create the precise lines to give the drawings a more realistic effect. I opened the drawings up in photoshop on a computer to develop them a little. With one I used the image I took of the campus and put the line drawing over it in white. The other i just added block colour to parts of the building and some surrounding detail as well. I believe these pieces are all rather successfull.