The answer to your question depends on the girl in question. That said, the 'Get big and cut all over' answer is good advice as your covering all the bases so to speak. This is an excerpt taken from The Definitive Book of Body Language by Alan and Barbara Pease that should give you some good info:
Is she a chest, legs or bum gal?
Women's sexual responses to men are triggered visually by certain aspects of the male body. When it comes to a women's favourite male body parts, women are universally split into 3 groups - legs, bums and chest/arms with bums taking %40 of the votes for first prize. Overall, women also look for athetic body shape, broad shoulders, muscular chest and arms and a tight butt. Even in the 21st century, surveys overwhelmingly show women still want a man who looks as if he can wrestle animals and fight off invaders.
Male bodies are purpose built to chase, catch and wrestle animals, carry heavy things and kill spiders
Women are attracted to a well-defined male upper body but most dislike the 'muscle man' body-builder look; a woman feels he is likely to be more interested in his own beauty than in hers.
1. Broad Shoulders, Chest and Muscular Arms
The upper torso of the hunting male is wide and tapers to narrow hips, whereas a woman's body is narrower at the shoulders and widens at the hips. Men evolved these features to allow them to lug heavy weapons over long distances and carry home their kills.
The male chest developed to house large lungs enabling more effective distribution of oxygen and allowing him to breathe more efficiently when running and chasing. In past generations, the bigger his chest, the more respect and power a man commanded, and this is still the case with most surviving primitive tribes.
2.The Small Tight Bum
A small, compact bum is the favourite of women everywhere but few understand it's magnetic attraction. The secret is that a tight, muscular rear is necessary to make the strong forward thrusting motion needed for successful sperm transfer during sex. A man with a fat ot flabby derriere has difficulty with this forward movement and has a tendency to throw his entire body weight into the thrust. For women, this isn't ideal, as the man's weight can be uncomfortable on her and make it difficult to breathe. By contrast, the small, tight rear promises a greater chance of doing an effective job.
3.Narrow Hips and Muscular Legs
Men's legs are attractive to women only insofar as they are symbols of masculine power and endurance. The powerful, angular legs of the human male are the longest of all primates and his narrow hips allow him to run swiftly over long distances to chase and hunt. Women's wide hips cause many women to have difficulty running, as their lower legs and feet often flay out to the side to balance body weight. Leading US neuropschology professor Devendra Smith discovered that women find male hips with a %90 waist-to-hips ratio the most appealing.
Is she a chest, legs or bum gal?
Women's sexual responses to men are triggered visually by certain aspects of the male body. When it comes to a women's favourite male body parts, women are universally split into 3 groups - legs, bums and chest/arms with bums taking %40 of the votes for first prize. Overall, women also look for athetic body shape, broad shoulders, muscular chest and arms and a tight butt. Even in the 21st century, surveys overwhelmingly show women still want a man who looks as if he can wrestle animals and fight off invaders.
Male bodies are purpose built to chase, catch and wrestle animals, carry heavy things and kill spiders
Women are attracted to a well-defined male upper body but most dislike the 'muscle man' body-builder look; a woman feels he is likely to be more interested in his own beauty than in hers.
1. Broad Shoulders, Chest and Muscular Arms
The upper torso of the hunting male is wide and tapers to narrow hips, whereas a woman's body is narrower at the shoulders and widens at the hips. Men evolved these features to allow them to lug heavy weapons over long distances and carry home their kills.
The male chest developed to house large lungs enabling more effective distribution of oxygen and allowing him to breathe more efficiently when running and chasing. In past generations, the bigger his chest, the more respect and power a man commanded, and this is still the case with most surviving primitive tribes.
2.The Small Tight Bum
A small, compact bum is the favourite of women everywhere but few understand it's magnetic attraction. The secret is that a tight, muscular rear is necessary to make the strong forward thrusting motion needed for successful sperm transfer during sex. A man with a fat ot flabby derriere has difficulty with this forward movement and has a tendency to throw his entire body weight into the thrust. For women, this isn't ideal, as the man's weight can be uncomfortable on her and make it difficult to breathe. By contrast, the small, tight rear promises a greater chance of doing an effective job.
3.Narrow Hips and Muscular Legs
Men's legs are attractive to women only insofar as they are symbols of masculine power and endurance. The powerful, angular legs of the human male are the longest of all primates and his narrow hips allow him to run swiftly over long distances to chase and hunt. Women's wide hips cause many women to have difficulty running, as their lower legs and feet often flay out to the side to balance body weight. Leading US neuropschology professor Devendra Smith discovered that women find male hips with a %90 waist-to-hips ratio the most appealing.
(and arse 
