100 Days of Sketching is a simple yet effective challenge to improve drawing skills in 100 days. I have also posted my challenge designs on Instagram.
Here's how it works,
1. Draw every day for at least 6 mins/day for 100 Days.
2. On any particular day, if you feel like it, draw more; if not, draw for 6 minutes.
3. Finish the challenge by either doing this in 100 consecutive days or 100 days in total.