Why lost cat posters are different
Dogs tend to travel; cats tend to hide. An indoor cat that slips outside is usually terrified, and a terrified cat stays silent and still, often just a few houses away. That means the most useful thing your poster can do is get neighbors to look in their own sheds, garages and under their decks.
That is why the lost cat preset fills in the note line with "Please check sheds, garages and under decks." Most people will happily look if you ask; they just do not think of it on their own.
Make the markings do the work
Many cats look alike from across a street, especially tabbies and black cats. The details are what make yours recognizable: a collar color, a white chin, a kinked tail, a notch in one ear. Add up to three in the markings field. Keep each one short, like "Red collar, no bell".
If your cat is indoor-only, say so. It tells people the cat is not a neighborhood wanderer and is probably scared and hiding, so it is worth a call even for a quick glimpse.
Search at night
Cats are more likely to move when it is quiet. Walk your block after dark with a flashlight; a cat's eyes reflect the light. Shake a treat bag and speak softly. Leave a familiar-smelling blanket outside your door. Then put up posters at the 3 to 5 house radius first, and widen from there.