Here is a great exercise in learning how to draw anything! I learned this while at Tea Time, courtesy of Lana Bachynski. The exercise is simple with only five steps and each only takes three to five minutes. A fun way to time each step would be to play a song and however long that song lasts is how much time you have. Pick something that you want to learn how to draw.
1. Just draw. Don't look up what it looks like; draw what you think it looks like either from what you know or guessing.
2. Now go find an image and trace over it. Tracing helps you learn the details, structure, and proportions of what you are trying to draw.
3. Next draw your item based off of the image that you looked up to trace. While doing so you will be thinking about things such as basic shapes and form.
4. Draw it again but this time in a different pose or perspective. This helps you understand the physical structure and form of what you are trying to draw.
5. Now that you have a basic understanding, take everything that you learned and draw your item without looking at any pictures or previous drawings.
You're done here but another great extra step that you can add in is to do 10 small thumbnails where you play with stylization of drawing your item. Push the shapes, poses, proportions, weight, and so on!
This is the toucan that I did while at Tea Time!