No, I don't mean writing all the boilerplate. It's simpler than that.

Just to take a random example, let's say the throwaway project you decide to do is build a custom button component in Angular. The steps would be something like this:

1. ng new buttons
2. (Answer prompts)
3. cd buttons
4. ng serve
5. (Create a custom button component in the new project)

I chose Angular because these days the CLI for it does almost everything for you. It's absurdly easy, and is the sort of thing it may actually be slower to ask an AI to do, because the AI will absolutely try to create a bunch of things in the project itself rather than through the CLI. And it will use Angular patterns from 2024 rather than anything current (such as Signals), because of its training data.

Not only is doing something like this (in whatever language you prefer) good practice for keeping your practical skills, it's a good reminder that AI is only one tool in the toolbox. If it becomes your only tool, well... The old saying about how if all you have is a hammer everything looks like a nail applies.