A style that is slightly longer than the chin, shaped and softened around the edges, flatters a square face. This gives the illusion of length to your face. Hair should not be cut shorter than, or in line with the chin, as this would make the face appear squarer. Avoid center partings and straight bangs. For someone with a heart shaped face balance between the forehead and chin is very important. Layered hair shaped along the face near the chin, thick at the bottom and with layered bangs will provide fullness where needed. Straight styles, which cling to the face, would accentuate the narrow jaw line and is not recommended.
Short hairstyles, like most styles, come in and out of fashion regularly, but they usually spend more time "in" than out. Recently, a long layered hair style was at the forefront of the beauty industry, but more recently, women have once again embraced the freedom and surprising versatility of short hairstyles. If you look at a picture of short hairstyles from the 1920's, you'll see that the hair is "marcelled." This was a process by which women's hairstyle was coaxed into tight, head_hugging waves. But if you look at a picture of short hairstyles from the 60's, you'll see that the women's hairstyle of that era was straight...often rolled on giant coffee cans to achieve the right effect.