So far, I've managed to find two of these elusive ties.
Meat Tie
Just look underneath the meat cubes behind the deli counter. The tie is right there.
Chicken Tie
You'll want to climb up onto the Deli counter where the scale is, then climb up onto the dairy display and over to the steel pipes. Carefully balance yourself on those pipes, and make a big step over to the vents to your right. The Chicken Tie is waiting for you there.