I come from more of a technical writing background and working with engineers and so I tend to over-explain (I call it being thorough) and then I don't want to seem like I'm talking down to someone and start glossing over things that maybe need some thoroughness. For wordy people like me, a picture is worth 10,000 words indeed!
Since I was self-taught many years before the internet I was able to use some general sewing knowledge, but things like why we cut a square with a single slash sometimes and why we cut with an X other times were usually not explained back in the day. Or why fabric grain is largely ignored nowadays, fussy cut all you want! Nor the math questions, which is one of the reasons sometimes we go one way or the other, depending on the measurement we know... and sometimes it is a matter of dealing with bias/stretch in fabric or just in the best use of the yardage.
Sometimes I think the why we need to do something is sometimes maybe more important than the how, we can achieve the same results in different ways. Some will be easier or harder, more consistent, or whatever it may be. I don't usually feel the need to starch my fabric, but I did a test block the other day where I would really recommend using starch and felt it was necessary for that pattern combined maybe with the fabric I chose to work with.
I did the Bonnie Hunter Frolic mystery this past year. I felt her instructions were really good and I'm thinking of doing this year's mystery and using her to guide me through pressing my seams to the side (I usually press open). Part of the problems I have with pressing to the side is there is the usual "press to the dark" but there are a lot of exclusions, and there are reasons why sometimes you do one or another. The problem we got into this year was not from her directions so much as trying to preserve the mystery element.
I very rarely buy patterns myself since I am able to draft them out. Exceptions were since they were direct copies of someone else's original work is I bought Elizabeth Hartman's Hazel Hedgehog, and the Guilty Quilter's Labyrinth Walk patterns even though I drafted both out. Still haven't made either yet -- but if I do it will be with clean heart!
Mostly the things I'm trying to do now are techniques, some of which can be taught in books like Karla Alexander's Stack the Deck concept(s) which I recommend, others are better in demos live or on the internet.