I love buildings, with watercolor you can create such complex structures but with simple tricks, I learned a lot in "youtube" tutorials and I usually pencil sketch them first, sometimes very lightly but I was thinking of doing more details with pencils next time and just lose watercolors to make it more transparent. I so such painting in one of the tutorials and really liked the way it was done. Pastel is definitely my favorite, watercolor I love and hate the same time, because it is easy to spoil but it is beautiful if it works :)