I naturally have bigger legs. It's just the way I was born. Do you want to know the one thing that has helped them look better? Lifting heavy. Squats and deadlifts gave my legs such better shape, tone and definition (and did not make them look bulkier, just the opposite in fact).
I used to get really intimated doing these exercises, but after time I got much more comfortable. If you have a squat machine (like this one) in your gym it can be a really great machine to help you with your form if you aren't quite comfortable with barbell squats yet.
I really like super setting these with calf raises - give it a try! I will often rotate the direction I point my toes (as shown) to activate different parts of my calf muscle.
Members of my site will get access to my favorite fat-burning treadmill workout which will be posted later this evening. http://nataliehodson.com/