I often carry my makeup bag and some cute shoes in my car. I don't wear makeup at work often (there are no guys here to impress, lol). So just throwing on some eyeliner makes me look great. If I'm really trying to make an impression, I may even put in my contacts.
My go to for going out after work is to wear some black pants and find a cute shirt to bring with me to work. But here are some great tips from the professionals on what you can do to go from Work Hour to Happy Hour.