Hint: A verb, popular on the back of shampoo bottles (as per usage instructions). The bubbles should also give a hint.
Random: This is going to sound weird, but I like the face angle in this. I debated adding that cheekbone definition or not, but I feel like it does help to give the impression that his face is tilted upwards. The hair outline is a little too dark for the rest of the tones in the picture though :(.
That's all for now!
~ Ignorant Awareness