Chances are you've collected an eclectic mix of plastic, wood, and metal hangers over the years. Remove all plastic and metal dry cleaning hangers (you can return those to the dry cleaner). Invest in a set of wooden hangers and non-slip hangers to streamline your hanging wardrobe. Everything will hang together nicely, and look real nice too.
Pro tip: Do not store clothing in dry cleaning plastic. Remove and dispose of (or recycle) the plastic wrap as soon as possible and let your dry-cleaned clothes air outside before placing them in your closet, if possible.