This is a far fetched anecdote (or actually two), and I am sure there are people here that will protest. But here goes anyway 
I play the guitar as a hobby. A couple of years ago I got the idea to practice on hitting one note, but to make it sound as good as possible. After doing that for a while, I raised the complexity and spent a lot of time practicing switching between two notes. (Mind you, this was when I already knew how to play, and played regularly in a choir). This was one of the harder things I’ve done, but it has actually improved my playing a lot. Some time after that I picked up a friends guitar. Before I started to play he told me that the guitar doesnt sound that good. But then I just hit a couple of chords and he just stared at me, “how did you do that? It’s not supposed to sound that good at all!!”.
Not saying this to brag or something like that, but rather that there is a power in simplicity.
I have also done the same when it comes to drawing (and actually, most drawing classes I’ve seen starts with the basic shapes… a lot). And while I am on the subject of drawing: Some time ago I saw a series of pictures that where all drawn with one continous line. It could be a dog, for instance, and you could see where the line started and where it ended. Somehow those pictures still managed to convay the image, weight and movement of the dog (or golf player, or car, or whatever) with just this single line.
I have toyed with the idea of practicing doing simple things in 3d. Of course, just making basic shapes is an exercise in clicking. But, what if I am only allowed to make basic shapes… what can I do with that? How much can I do with a cube to make it look good.
Same thing goes with animation? Infact, here it is a bit easier. I can try to animate different simple objects to make them look as living as possible.
And of course, same thing goes with all the other crafts in the 3d-industry. I think… but it would be interesting to see more examples of simple things to do as a practice, where the challenge isn’t the technical aspects of it, but the artistic.
McWolfe