Make a list of things you could be half of... half-Cherokee, half-Scottish, half-elven, halfling (for you D&D fans out there, heeyyyyyoooo), half-vampire, half-horse (isn't that full centaur?), half-centaur (okay, now what's that make you?). Don't stop there, though. Keep making your list. Take your time, have some fun. Half-assed, half-hearted, half-dead, half-cockroach. Like a cup you could be half empty, or half full. Half right or half wrong. Maybe you're half a person (you choose which half), or half of a siamese twin.
Write a poem exploring this half identity. How does it struggle with the other half of you? Does it make your life easier or harder? Maybe both? How does society view you, or does it even know? Perhaps it's a secret you keep. What are the stakes in keeping your secret safe?
Check out Half-Vampire by Aaron Belz at Meaningless.