The full post has some comments about background textures and sketching.
I was hoping to post a video on binding the Portrait Party books today but hit a technical snafu. That will come another day.
Instead here are more faces from old yearbooks. A couple weeks ago in my day-long class I was trying to explain something to my students. I reached for my samples but couldn't find the example of "that" I wanted.
Wednesday I realized as I was working on this page spread I was making my point—so before I forget—if you have a background texture and color it is often fun to draw over it and then isolate the figures by painting around them, retaining the texture inside the figures. (If you follow the link and watch the video you'll see another example of this at the end of that journal. I paint around the figure of a dog that was sketched across the spread. One page had been pre-painted the other had not. Painting around the dog helps meld the two different backgrounds into something a bit more cohesive.)
On the above page spread I used fluid acrylics and acrylic ink to create a background of pink and Payne's Gray. Drips, streaks, splotches, some pockmarking from spritzing with water—all that. I had hoped to do a painting on that page. I even worked beyond this page to "save" it, something I rarely do. But it was time to finish the journal (only two spreads left), so I picked up the pen and started sketching. You can follow the time tags around the page to see the sketching order. When I was through sketching I took M. Graham Payne's Gray gouache and painted around the figures. (The note was already written on the page before painting the background, but I knew when I drew the last portrait and the outline of her feather neckline that I was going to be writing something in that space.)
So for my students, that's what I was trying to explain the other day. For everyone else, well it's something fun with which to play. Note that the color you elect to use to isolate the images can change the mood and tone of your piece, so have fun experimenting.