whats your favorite and effective way to build muscle?
I use Bob Greene's 8 essential dumbbell exercises, and they work pretty good for me. They can be found on oprah.com.
A good way to build muscle is to lift weights and constantly challenge your muscles with increased resistance, different exercises, etc.
This is a good resource for women's weight training - Women's Weight Training
Don't be afraid to lift those heavier weights (10 lbs and up)! Once you can easily do 3 sets of 12 reps of a certain weight, add more resistance. This way, you are constantly challenging yourself. Also, switch your routines up every now and then.
Food also plays an important part. Make sure you're getting adequate protein, carbs and healthy fats, all in a healthy diet of whole, clean, natural foods.