Accordingly, men customarily wear these pins on the left side of their suits, closest to their hearts. If you have multiple lapel pins, take care to arrange them on your clothing in a respectful manner. However you choose to wear your pins, be sure they are displayed in a way that makes you the most comfortable.
What is the most popular size for a lapel pin?
As a lapel pins can be design and custom made in different shape and size. But the most popular size for lapel pins is 3/4 inch, 1 inch, 1-1/4 inch, 1-1/2 inch and 1-3/4 inch. and 1-1/2 inch, 1-3/4 inch for custom coins.
The Proper Way To Wear Multiple Lapel Pins : Men’s Formal Fashion