Cherubs are often considered baby angels or infants depicted as angels. While they are sometimes comic, religious depictions of cherubs show them as fragile, wide-eyed and peaceful. Cherubs bowing before an angel or hiding from God could express your faith. A simpler religious tattoo design is a cherub or a pair of them in prayer.
Cupid is known worldwide as a symbol of love. His legend dates back to Roman mythology when he was the god of love. A Cupid tattoo could show your dedication to true love. A smaller idea is simply an arrow piercing two hearts, the classic symbol of Cupid bringing two people together. A Cupid tattoo is great to get with your spouse or significant other as it is a permanent reminder of your love.
If you are a lover of art, then there are literally hundreds of Renaissance depictions of cherubs doing any number of things, including fighting battles, sleeping with lions and fooling men. By browsing the works of Raphael, Michelangelo or other Renaissance painters, you could bring in an image for your tattoo artist to recreate or interpret.
A solemn cherub can be a great memorial to a lost child, be it yours or a loved one's. A wreath or ribbon could encircle the cherub with the name of the child that passed away. This would be a lifelong tribute to someone who was taken too early.