/ic/ - Artwork/Critique

Could someone help.

Whenever I start drawing a figure I start with the head as a circle. I use that circle as a canon to get the proportions right for the other body parts (I assume this is how you do it). After construction I move on to details and I always end up making the head too big. I use the circle as a guide to draw the head but usually the details would extend way below the original circle guide I drew.

Am I doing something wrong or is there something I should be doing?

Sorry if I'm not being clear I drew pic related to hopefully get my point across.