When you go out looking for your kitty, DO NOT yell. You will frighten her if she is not used to hearing you yell. Just walk around talking to her. Cats have exceptional hearing, and she will be able to follow your voice. Think about it, when does your cat hear you yell? When something is wrong! Just keep talking as if she is right near you, and if you are lucky, you may find her right away! You could also walk around shaking the cat food box, or the cat treat container.
Because my cat is an escape artist, I have taught him that hearing his name twice, means there are goodies for him. Now I just step outside and say "Bruno Bruno" and wait. I never teach my cats to come to 'here kitty kitty' because that is how everyone calls cats, and this is my cat.