Customary is used to describe things that people usually do in a particular society or in particular circumstances. It is customary to offer a drink or a snack to guests = usual
in accordance with convention or custom; "sealed the deal with the customary handshake
Customary is used to describe something that a particular person usually does or has. Yvonne took her customary seat behind her desk. = usual
in accordance with convention or custom; "sealed the deal with the customary handshake"