I Have a Bird in My Pocket by Erika Salmon | Canvas Tokyo

I drew this as a personal favor for a friend.

What I enjoyed drawing most were the nostrils (cute little concentric circles) and eyes (bright, black, intelligent beads). What I struggled with most was shading. Also, if you are wondering why it has a crease, it's because I put it in the sleeve of my chanchanko (like a hanten but sleeveless) and forgot about it for a day.

Medium: pen/Prismacolor colored pencils
How about you? What do you like most about drawing birds? What do you struggle with most?