When I was first starting out in 3d, I came across this page on CGScociety posting a series of free models to practice lighting and rendering. I thought it was an amazing idea, and naturally, completely forgot about it. So a few years go by and after rediscovering the same page for probably the fourth time, I decided to take some time this year and try to knock out as many renders as I could with the best quality that I could achieve. I scheduled it down into 3-month blocks, aiming to get 4-5 renders done per block. I also wanted to experiment with different moods and environments trying something different for each scene.
The link to the challenge and the models used can be found here: https://forums.cgsociety.org/c/lighting-and-shaders/lighting-challenges