One must understand Indoor cats go into a fight or flight mode when outside. They MAY or may not recognize their name or your face. They WILL recognize, in most cases, sounds or smells: the sound of a food can opening, a favourite toy, etc.
Take a moment and think of all the sounds that perk up their ears and make them come running to you. In about 5 minutes of thinking, my wife and I came up with about four. If you cannot take the sounds with you, record them on your smartphone and play them back around your house.
Indoor cats lost outside become active in the evening usually around 7 pm-5 am. The best times for you to call names, make sounds, flashlight shining of eyes and have active searches 11 pm – 2 am.
Get permission from your neighbours to look around their yards. Going onto someone’s land my start and argument that could scare your cat away if there. Use the daytime to post flyers make calls and engage others to help search. (More details below)
Your cat will typically hunker down within just a few hundred yards from your home unless spooked. They can get very small and into places, you may not think of. Take a flashlight, get under bushes, decks, and in sheds behind garbage cans, and so on even during the day.
Look, call and bate near storm drains. Storm drains are very small and dark places for a cat to hide. Note: Cats have a floating collarbone that allows them to get their body into any space where their head can get through.
Trapping: Get humane traps (Google hunting supply stores) and place them near the house with favourite foods. (sardines are also a great lure). Place the food outside the trap a few feet away eventually bringing it closer and closer before putting it in the trap.
Scent Strips and baiting: Cut up some scent strips out of your old clothes or bed sheets etc. (one-inch by three-inch strips) and hang them low enough to the ground but high enough for the wind to take the smell. (I wore a shirt for five days to make it smell as strong as I could.) The smell can last 3-5 days. Cats can smell over a mile depending on wind conditions. Then make the scent strip and “Cat Chum” (Described below) trails back in the most direct and safe way to your house and/or traps. Do not lay Scent strips and Cat Chum on top of each other. You can and should use both but keep them at least three or more feet apart. Also if possible, leave windows open in your house at night, sometimes your cat is unable to remember what house the smell of the house in the night air draws them to home.
Cat Chum: Mix a gallon of water with 1-2 cans of tuna/sardines to make “cat chum”. Make straight lines of chum to the trap/house. DO NOT place your scent strips in your chum mix when laying them down. When laying down scent lines concentrate it near the opening of the trap and run it in a straight-line way using less and less as you get further away. Find places to make small pools, discarded bags, cups etc.
Litter: Put the UNCLEANED litterbox outside. For Multi-cat homes take the litter, bag it then place the litter out further away from your strips and chum. It is usually more pungent, making the scent carries further to draw in your cat. But be careful on this tip. The litter box can draw in other cats that may push your cat away.
Making Cat Shelter: Get/use a small cat carrier that is just big enough for your cat. Place a blanket that smells like you inside. Place the carrier under cover somewhere tight and dark if possible. Leave the door open. Cover it with another blanket that smells like you to protect it from the elements. Place food and water just outside of the open door. Place a favourite toy inside. When approaching the shelter do it slowly and from the front. Calling softly, shine a flashlight inside and look for the eyes.
Do NOT chase them. If you hear or see them REMAIN CALM sit down, softly call their name, make the sound they recognize, open food and LET THEM COME TO YOU. It may take hours for this to happen.