I really love this, & it's helped me many times over the past years.
I'm mostly writing this comment because I finally figured something out and want to share it with others: one of the tips (the kitchen timer) wasn't helping me consistently, and I didn't know how to fix it. I had a kitchen timer and all, but when I set it, it was mostly just annoying me and I got frequently distracted during the first 20 minutes. it helped enough that i wanted to keep trying it, though, so I was pretty sure I could fix the issue.
finally, I realized two things: for me personally, the kitchen timer wasn't great for less active tasks (writing, for example), but it was fantastic for physical things like Cleaning, etc. second, if I got distracted in the first 20 minutes, I could just set it for 10-15 minutes at a time. the more frequent interruption of resetting the clock was beneficial because it was less an "interruption" and more a reminder to stay on task.
so yeah! sharing that in case it helps anyone else reading the comments.