There is a book called tiny habits by B J Fogg. The part about it, that separates it from other habit forming systems. It shrinks the habit or in this case what you're trying to learn. Modeling tutorials can get you so far. What they don't tell you is you need to use the same process somewhere else. That isn't always easy.
With the context in mind, here is the question. How do you turn tutorials into tiny habits? Modeling, texturing, and animation. If you are teaching yourself to be a cg artist, or animator, what are the smallest things you can create to learn or apply the tutorials you read or watch?
You have almost answered your own question.
Simply, apply what you learn in the tutorials in to your own projects.
For example, you follow and complete the Press Start course, then using the skills learnt in this course you could create another style of console.
The key is to practice as much as possible.
Habits are by definition, regular tendency or practice.
So tiny habits in the context of learning Blender, practice different modeling techniques, practice texturing, practice animation.
practice, practice, practice.
The mistake would be to complete a course, complete another course, complete another course, and on and on.
You really need to try create something of your own to get that practice between courses.
I think the tiny habit that worked for me the best when I was learning Blender was the following: As soon as I turned on my computer, I opened Blender and CG Cookie, absolutely the first thing always. Because it is so easy to get sidetracked with everything you have access to that steals from your attention on the internet. If I was working on a blend file, opened that up first and something, no matter how small, no matter what anything. Don't open the web browser, don't open the music app, always Blender and CG Cookie first. This way I got absorbed quickly into productivity mode, my brain was like well since I'm here, I might as well continue doing this.
I think Adrian's suggestion about completing a course, then doing something similar is spot on. Or, if you're going to do another course, stick with something similar. If you did the press start course, do the helmet or motorcycle course.
Eventually you're going to want to do your own hard surface model project, or whatever it was that you studied, so that you have to plan things out yourself, and when you run into a problem you have to solve it on your own. The courses largely "solve" most of the problems for you. There may be one or two oopsies, but it's entirely different making your own say stand up arcade system after doing the "Press Start" course than being walked through another hard surfacing course, even if it's more complex. (Or just choosing a different console to model.)
You need to think about how to solve some of the topology and presentation issues yourself.
I think I probably spent a little too much time hopping around and am trying to get better about repeating things with my own projects.
Edit: A couple edits.