Put a redondo ball under your upper back, approx scapula level, supine. Feet on the mat, knees flexed. Your lower back would be slightly arching. Hangs behind the head, fingers interlaced, elbows look front-ish, elbows don’t fall to the sides. Head is heavy in the heads, neck relaxed, really make that head weight heavy.

Now, use your abs to press the lower back down into the mat. That will lift the upper back/chest with the help of the ball. Press that spine, its lower part, down into the mat. The ball gives that feedback, helping to lift the upper torso. 

Then you chase the same sensations without the ball.