If some stuff is basic, it's not stuffed by any other stuff (except maybe by other basic stuff, symmetrically), and all other stuff is stuffed by it (or maybe by other basic stuff). We'll search for which stuff, if any, is (more) basic:
Stuff that represents (e.g., thoughts), or stuff that is (mis)represented?
Existing stuff, or merely represented stuff?
Actual stuff, or merely possible stuff?
Spatiotemporal stuff, or stuff from beyond?
Places and times, or stuff at places and times?
Present stuff, or also past/future stuff?
Whole stuff (e.g., the universe/multiverse), or its parts?
Stuff that happens, or stuff that stuff happens to?
Stuff with features, or those (bundled-up) features?
Features had by stuff, or also unhad features?
Nonmental stuff, or mental stuff?
Evaluatively neutral stuff, or good/bad stuff?
Or does stuff just stuff stuff, with no start?
And we'll search for how (more) basic stuff stuffs stuff:
Naturally, or artificially (e.g., by being thought about)?
By cooperation, or by mere coexistence, with other basic stuff?
By causing, lawfully probabilifying, or necessitating stuff?
Can nonmental stuff completely stuff mental stuff?
Can nonethical stuff completely stuff ethical stuff?
Can stuff from beyond completely stuff spatiotemporal stuff?
Can the absence of stuff completely stuff stuff?
That's more than enough. If staff gets guff, we'll slough off some fluff.
A term paper and two or three quizzes (rough). If staff gets guff, tuff.