Body scanning - right way of attention moving Practice - Mindfulness of body

When I move attention part by part in the body I don't feel sensations in every part . Is this right ? Or should I feel sensations in all body parts ? 

Sometimes I do quick sweep of attention from head to feet . I do this at any moment during the day when I remember to be aware of my body . 
Would this be helpful for practicing  mindfulness of body ? Or is there any better way of doing this ?
When I do a body scan, I do a visualization of a "golden nectar" slowly filling my body from the toes all the way to the top of my head. This is a way of helping you keep a focus of attention to the body. For me, sometimes as I am doing this technique, there is a sensation of warmth that I feel or think I feel as my attention to the body scan grows.

I hope this also helps a bit during your meditation practice.