I do apply these tools equally to my hobbies and personal projects.

I think it would be easiest if I attempted to give advice that is tailored to your particular hobby / personal project. Something like "learn piano" is going to be treated a little differently from "maintain a blog" which will be treated a little differently from "research nutrition".

But generally, I find things go well when I make timeboxes for these projects (set aside work X hours to work on this per week) and then break down the hobby into actionable tasks.