Sketchbook Studies for Future Paintings

I am continuing to paint in my sketchbook from my Italy photos.  I am finding working in my sketchbook travel journal helpful in two ways. First, I am completing my sketchbook so it will chronicle my trip in paintings + a little writing. Second, since my journal pages are small , about 5"x8" I feel free to try out new paint colors and combinations since I am going to use them as studies for future paintings.