It's not how long you practice, it's how consistent you are. Twenty minutes each day will bring better results than 2 hours of practice twice a week.
Try to practice about the same time every day and lock yourself in the bathroom if you need to in order to be in a quiet environment. No distractions and for heavens' sake turn off that cell phone.
This time is YOUR time. Make it a point to announce this fact to your friends and loved ones. You are not available to anyone during this time.
Have plenty of water available during practice sessions.
Bring a positive attitude and clear goals.
Practicing should be a joy and frustrations kept at a minimum.
Sing with Joy!
