Thank you! That is a great question. I generally use 3 colors for the shadows (one purplish on Hard Light and two cold blueish-greens on Multiply). But for this character portrait, I added a third overlay shadow with a purple tint. For the highlights, I wanted a golden sunlight glow. I used both "add" and "overlay" with the same golden yellow. I like to push the cold/warm contrast. This makes me want to include a screenshot of my Highlight/Shadow layers and their blending properties on my next post :]