Learn how to communicate with your stylist...
The most reliable way to make your hair-colour wishes clear to us (your hairdresser) is to bring in a picture of what you're envisioning.
But understand that's just a jumping-off point—your colourist will (and should) tailor the colour to your complexion. And don't try to use 'hairdresser talk'. Instead, describe what you want as if you were telling a friend ("natural-looking highlights that aren't too stripey," for example).
And another tip: always let them know what you don't want!