Be accepting. The child who is grabbing more than one piece of candy may have poor fine motor skills.
The child who takes forever to pick out one piece of candy may have motor planning issues.
The child who does not say "trick-or-treat" or "thank you" may be non-verbal.
The child who looks disappointed when they see your bowl may have an allergy.
The child who isn't wearing a costume at all might have a sensory issue (Sensory Processing Disorder) or autism.
The "too big" or "too old" child may be developmentally delayed.
Be nice. Be patient. It's EVERYONE'S Halloween.
(PS - Shrek and Fiona hand candy to anyone on the edge of the swamp. Especially if you look like a parent that works hard, is tired, but by God, you will make sure your child has a fun Halloween!)