If you want to keep your casual outfit you can never go wrong with cross body handbag.It's a much more practical alternative for a busy day or for days when you're not at the office or don't have to pack a lot of things with you. Black handbag can be combine with jeans and shirt or little black dress.
Source: https://www.accessoriesandstyle.com.au/bags/bags-styles/crossbody/