The proper placement of a tie tack is approximately half way between the knot and the end of the tie. A tie tack serves the purpose of holding a tie in place, and it is also a fashionable accessory.
A tie tack should not be too close to the knot of the tie or too near the end, says GQ Magazine. It should be just covered when the top button of a suit jacket is buttoned. The exact placement is a matter of opinion and depends on the wearer's preference. Tie tacks pin the tie against the shirt to keep it from falling forward when the wearer bends over. They also help to keep a tie clean when working or eating.
A tie tack has a pin that goes through the tie. This is the decorative part that is visible. A thin bar attached to a chain that goes through a button hole anchors the other end to the shirt. The placement of the tie tack depends on the location of the button holes on a shirt. Tie tacks come in different styles for various occasions. They can be casual for everyday wear or quite fancy for more formal occasions.