Keep in mind that you must maintain a neutral spine position, arching and curving your back places stress on the intervertebral disks, and lets your muscles slack off. Doing dead lifts propperly can help protect your back in your day-to-day life because deadlifts teach you to keep your lower back rigid against a load. Keeping your back in a neutral position helps avoid injuries when lifting heavy objects from the floor.
Don't roll your shoulders, your hip muscles should move the weight, not your shoulders. To make sure you push from the heels (to protect your knees) curl your toes up. Start the lift with your shoulder blades directly over the bar. This will ensure that your hips and knees are at the right angle.