A mob-like crowd, edging close to the stage, people holding baskets of rotten vegetables or stones, the local law enforcer (police/sheriff/lord/constable/official/captain etc), rope, noose, a block of wood or platform, trapdoor, wooden structure and steps. cross beam, supports, pulley for trapdoor, priest to deliver last rites, guilty prisoners in shackles, black hood, executioner, steps, many faces pulled in expressions of hate or excitement, only a few with disgust, people shaking fists and spitting, children climbing up on barrels or risers for a better view, spectators lining the roof of nearby buildings, faces pressed to windows, a courtyard area surrounded by buildings or with the prison close by, women selling wares to the gathered crowd (food, drink, etc), men close at hand with weapons of the era to prevent escape, bits of rotten produce littering the steps and gallows platform, perhaps smearing the accused's face or clothing before the law puts a stop to it
The crowd cursing, yelling screaming, shouting, excited murmurs, the hard raspy breath of the prisoner, the drone of the religious representative offering last minute prayers or urgently requesting the prisoner repent his sins, confess, etc. The thump of heeled boots crossing the planks of wood, the dragging footsteps of the condemned, begging, pleading, crying, moaning, weeping, the official addressing the crowd, giving voice to the crimes the person had been found guilty to and the punishment, the thunk of the trapdoor opening or block of wood being kicked over, the creak of a taut rope, the snap of a neck or squirm and shuffle of fabric as the condemned chokes to death, the final exhale, the clump of cabbage or rotten apples bouncing across the platform, the whump of the body hitting the ground or into a waiting wagon bed after the rope is cut or released
Stale sweat, body odor, dried blood, dirt, dust, the smell of pine or aspen if the platform is newly constructed, weather (sunshine beating off the planks of wood, flowers being carried through the air, rain, etc), cow or horse manure, smoke, rotten produce, the foul stench of breath and fear inside a hood used many times
Sweat, tears, spectators meals brought from home (bread and cheese, water, fruit, etc)
The pinch and rub of raw wrists against rope, shoulders pulling and painful at hands being bound behind back, the solid planks underfoot, each step heavy and full of foreboding, flinching at being touched or trying to avoid being hit by a projectile, the hard, digging grip of a lawman pulling you to the gallows, dragging your feet, swinging wildly side to side, trying to break free, pulling back as you're being dragged forward, jerking head to resist the noose, a shove to the back or side to keep you on route, sweat dripping down neck, chests and sides, taking the step up onto a block, flinching as the the weight of the rope settles around neck and then is pulled tight, tense muscles, teeth clenched, hands turned to fists behind back, chest heaving with frantic breaths wondering which will be the last, the sudden drop and weightlessness, then the final tug and jerk of dead weight and darkness.
--The words you choose can convey atmosphere and mood.
Marcy looked on, ignoring the satisfied shouts from the crowd. She expected to feel something more as the man who'd raped her swung from a length of hemp like rotten fruit too stubborn to fall from the tree. Hands patted her back and squeezed at her wrists before moving off, eventually leaving her alone in the dusty courtyard. In that moment she understood how much she had in common with the dead man--both had all the good life had to offer stolen from them. What justice was it that his reward was death while she had to remain in this world, living on with nothing but pain?
Halfway through a hot, stale breath, the floor gave way beneath Jess. For the smallest moment the jeers of the spectators faded and he was rewarded with an exhilarating memory of jumping off his uncle's barn roof with his cousins. A sharp, stiff jerk brought him back and as the rope choked off his breath he understood: no soft pile of hay waited to catch him this time.
--Similes and metaphors create strong imagery when used sparingly.
Example 1: (Simile)
The mob crowded the gallows like hungry jackals closing in on a waiting feast.
Example 2: (Metaphor)
A yoke of guilt bowed the man's shoulders and sent his gaze to the ground as he approached the gallows. He didn't look up, not once, not even as the noose settled around his neck.