Select representative pieces from across the year's four units and write a reflective introduction naming the specific skill each piece demonstrates.
Portfolio curation is a deliberate act, not just gathering everything written this year. Choose pieces that together show range -- argument, research, memoir, literary analysis -- and growth, such as an early piece placed next to a later one to make a specific skill's improvement visible, rather than only the pieces that were easiest to write.
The reflective introduction is a short piece of writing ABOUT the portfolio itself, naming why each piece was chosen and what specific skill or moment of growth it demonstrates. This introduction is itself explanatory writing, deserving the same care as any other piece.
Mastery looks like: They select pieces representing the year's range and growth, and write a reflective introduction naming specific skills each piece demonstrates.
Common stumbles: Choosing pieces for vague reasons ("my favorite," "my best") without naming any specific skill or moment of growth.