I have four dresses that are in a basement closet with my wedding dress - two are formal but bought this decade (the purple 20's and green 50's I wore for the challenge and do wear once a year or so). Two are left over from the last two Halloweens and should probably be donated again (they were both thrifted).
I love costumes and dressing up, but don't like to store anything that is going to be unworn really. I have two 3"x2" ft plastic tubs in my basement. One has any paperwork or small items of strong sentimental value, the other has silk sarees I bought and wore living in India, and my husband's flag from his country of origin, stuff like that. Those are the only sentimental but not useful storage places in my house. I generally start from what I have in current clothing for costumes, and thrift a few other parts if necessary for a party or something like MovingFashionForward suggests.
I don't think your closet is characterless, even if it's contemporary.