Restriction: Make something in which the sense of smell is an essential component.
The dust from an inside rim of an old, disused harp as it slides up your nose and makes you sneeze in the grainy air of the warehouse attic. When you blow your nose and open your eyes, the magic has drained from the place and the stench of mothballs and cat litter makes you vaguely ill.
The sweat of your old landlord, somehow here in your new apartment in a new city, travelling with you. Embedded, perhaps, in the old shirts you wear on weekends when you swiftly give up on exercising and sit in the glow of the television, wiping the orange goop from fluorescent snacks on your belly.
An unreal glowing fake fruit perfume dripping off an oblivious woman who sits down next to you on the bus, like candy pushed past the point of sweetness into the realm of rotting meat and headaches.
The acrid pumpkin seeds, burnt now – your kitchen timer battery ran out – blackened seeds filling the oven with soot and the air with a smell of burning harvests.
The twinge of regret when you remember a cruel prank and it brings you all the way back to the schoolyard, him standing there in relief, the crisp fall air blowing by as you relive this moment, confused in the memory with the fresh asphalt patches on the parking lot cracks. The chemicals sound his defeated, watering eyes in your nose.
Pine needles crunching underfoot with that vague gasp of freshness in the drying husks as you stomp through the darkness, unafraid of the noises in the warm summer night. The campfire smoke follows you on your clothes, but you do not turn around to return to the circle. You keep walking, and soon you only hear the swish of the carpet of needles on the forest floor and the breath as it leaves the tip of your nose into the humid air.