I've learnt this way of thinking through teaching myself to code over the years but it's pretty applicable to most skill based things I'm learning.
It's pretty simple, but I often times overlook its power.
If there's a large, tricky challenge that I can't quite get a grasp of, I'll break it down into a small, manageable project and see if I can work through the problem that way.
Make it low risk
The beauty of the sandbox approach is there's little to no risk, there's no hesitation of messing anything up, this is only for learning purposes, the equvelant of grabbing a scrap piece of paper and scribbling down some ideas.
Challenge:Learning line-work Example: Breaking down others work in small chunks
Digital sculpting example
Challenge: Sculpting a face Example: Experiment on a sphere first
Challenge: Pull all newsletters from the Convertkit API and having them show up on the website Example: See if I can get one showing up correctly first