Bluebooking and Citation
Your tutorials on most of the core 1L subjects are excellent. A great way to further help 1Ls and even add more relevant content for rising 2-3Ls who might be starting/competing for a journal position, a set of tutorials on Bluebooking and citations for journal would be awesome.
I can't speak for other schools, but I learned pretty much nothing about using the Bluebook during the 1L and have taught myself everything I know from working through practice citation exercises in preparation for our journal competition. I am sure a lot of people would make use of some Bluebook tutorials should you make them available, especially on some of the trickier/less intuitive aspects of Bluebooking.