Aspect 1: Jack-o-Lanterns
When people see Jack-o-Lanterns, people automatically think of Halloween. Many families are drawn to the sight of pumpkins, whether they're cut out yet or not, because people cut out faces and put lights inside them when they place them out on the porch.
Aspect 2: Fall Cliches
Upon seeing certain things, you automatically think of fall, and it gets you into the Halloween spirit. Some cliches for fall include red/yellow leaves, pumpkin spice lattes, owls, bats, etc.
Aspect 3: Scarecrows
While scarecrows are farmer cliches, they are also fall/Halloween cliches. Jack-o-Lanterns, bats, and scarecrows are among the top (personally) most recognizable fall props.