The thing about human psychology that just fascinates me is that the most important thing to anyone is their identity. Your name, your age, your height, anything that concerns describing you is a very important thing to you. Your name is very personal because not only is it who you are, as you associate everything about someone to the name generally, but it is the interface that connects you to other people. Personalized groomsmen gifts are great because they show both the persons name but the gift is linked to them personally. The trick here is to show them you appreciate who they are and link some memories of you and them to the gift!