Working on an android tablet for over a year has changed the way I think about creating art. I'm still finishing up another related post which I reflect on how I create art. One of the points is that I see this digital mode of creating as less a digital version of real world tools. Looking at creating digitally, I no longer view a 'brush' as a digital version of an actual brush (or pencil, or chalk.)
For myself, looking for digital versions of real world tools, or thinking in terms of real world tools while working digitally is limiting.
Outside of composition, I usually attempt to think in terms of light. How can I deliver the right light to the piece. Some of my flatter pieces might focus on composition, but aside from those, i'm looking for light.
Textures and patterns add some visual interest, especially when layered in correct dosage.