Suggestion for Tips and Notes Sections
This is a minor suggestion that I think should be easy to implement.
Would it be possible to add, at the TOP of each Skill section, a verbal pointer to the actual Tips and Notes? It could be something very simple like "Please see the section below the Lesson links for information that will prepare you for the exercises in this Skill."
An alternative would be to put the Tips and Notes section itself at the top of the mail Skill page. But that could be tiresome for those who like to go back and repeat past lessons for practice, because it would mean scrolling way down, past the grammar explanations, to get to the actual exercises. Unless there could be a link to exercises section... say, "Click here to get to the Lessons for this Skill."
Just a thought... if it's something The Powers That Be at Duolingo could be persuaded to do!