Sometimes the only message that people wish to convey when presenting someone with a gift is that it was meant to be special and personal. It is common to see engravings that have nothing else in them other than relationship terms: mother, father, sister, brother etc. If this is what you want, but would still want the engraving to be a little bit more classy use the language best suited for the job, Latin. Here is a quick rundown of the words you can use. All the terms are in the correct cases. All it takes is just to have them engraved!
Uxori meae – To my wife
Uxori meae carissimae – To my dearest wife
Marito meo – To my husband
Marito meo carissimo – To my dearest husband
Amico meo – To my friend (masc.)
Amicae meae – To my friend (fem.)
Amicis meis – To my friends
Matri meae – To my mother
Patri meo – To my father
Fratri meo – To my brother
Sorori meae – To my sister
Filiis meis – To my sons (to my daughters)
Uxori et filiis meis – To my wife and my children
Marito et filiis meis – To my husband and my children
Filio meo – To my son
Filiae meae – To my daughter
Avo meo – To my grandfather
Aviae meae – To my grandmother
Transcribing modern names into Latin is a whole different story, but the good news is that you don’t really need to have that for your engraved message.