As an EX- Stylist, the advice I can give you is to look at styles you like in magazines. If you think you really like it , cut it out and cover up the face of the person wearing the hair. Then hold it up to the mirror next to your face, or paste a small photo of your self in the face.
Is the facial structure the same? Are the colors close to each other? Can you actually style it the same? If there are bangs & you don't have any, can you adjust?
So many people think that they will look EXACTLY like the photo and are disappointed when they get the cut and it looks different.
AND, don't make a DRASTIC change all at once. Most people I worked on who would cut more than 3-4 inches off their hair at a time hated the style at first, and then of course, it becomes the stylists fault...