In autumn of 2009, artist Jake Parker challenged himself and other artists to create one ink drawing a day for the entire month. It was designed to improve inking skills and develop positive drawing habits. He called this month Inktober, and since then it's grown worldwide with thousands of artists taking on the challenge each year.
This is an example of a monthly art challenge. Participants are given an art prompt for every day of the month, and the challenge is simply to use the prompt as inspiration for artwork, which is then digitized and shared on social media.
What makes an event like this so effective is the built-in accountability and audience. When an artist commits to doing a monthly art challenge, they commit to practicing their craft on a daily basis, not just for themselves but for the community made up of the other artists committing to the same thing. They mark their resulting work with hashtags associated with the challenge so that everyone following the event on various platforms can easily find their submissions.
So if you want some inspiration to help stretch your art skills, or if you simply want to view artwork from all over the internet, consider looking into some monthly art challenges. Inktober is only one of many, and a quick search online can yield art challenges for all months of the year, in all kinds of mediums.
Maybe one day we'll host one specifically for colored pencils!