If you have a man who isn't taking great care of his hair, or is in dire need of a makeover, it may be a great idea to mention to him which celebrity hairstyles you like. If he doesn't seem to be paying attention, you may want to accompany him to his barber appointment and quietly suggest it to his barber instead, that may work better.
Remember that hair grows forever, it doesn't stop. If you go out on a limb, drastically change your hairstyle and end up hating it, it can always be changed to something else, another style or color. Talk to your stylist to see if they have any fun celebrity hairstyles for you. You never know, they may have a style that they have been dying to try on you, but never had the opportunity before. Most hairdressers won't try to push a new style on you (nor should they), but if you ask, they love to share their creative side.