Today, we are focusing on using correct posture throughout your workout. This is a huge topic and I feel that it can make a difference in your workouts. Correct technique and maintaining good posture keeps your body in-line, over-compensation free, and decreases your risk of injury. You might have to decrease your weights in order to do so, but it will be worth it in the long run. I have a few demonstrations below to help you picture a few exercises.
Push-Up: Notice how his body is in-line from his neck to is feet. Try not to drop your head while performing this exercise.
Crunch: Keep it simple, do a crunch not a sit-up; better on the spine. Also notice how he is not pulling on his neck. Try to keep your head back and in-line with upper spine.
Standing Tricep Extension: Notice how her feet are shoulder width apart, head is up and in-line with spine, and her back is not hunched over. You will notice one of these three struggle if you are trying to lift too much weight.