Best advice when getting a tattoo to represent a child?

I am getting two tattoos to represent each of my children. I want something completely unique (no names, birthdays, hand or foot prints, etc). What is the best advice that you can give to help me pick a unique and meaningful tattoo for my boys? I will probably design it myself and have someone draw it, but I just can’t think of the best way to represent them without having a tattoo that everybody else has. Thanks!

Focus on their personalities. What really stands out in each of them…