When it comes to "writing a tutorial" for the benefit of your own knowledge, it's been proven to work. This is very good advice when it comes to personal gain. However, for the sake of beginners and content creators that are active in the tutorial community, please consider throwing out these lessons when you're done. It might help someone out there at some point but you have to take into account your initial motive: personal advancement. Lessons that are taught out of passion for teaching and advancing the knowledge of those around you are often the best because they come from a selfless place. Lessons created for the creator's own advancement are often not as helpful. This is something I struggled with when creating my own tutorials. Was I creating it out of love for teaching others, or was there some hidden motive that even I might not be aware of?
This is simply my own opinion, take my comment with a grain of salt. I'd be interested to hear what others think about the prevalence of "beginner" tutorials juxtaposed with an apparent lack of those that would be considered "advanced".