Do not make it harder than it is! All you need to do is get the right proportions. Begin by drawing a shape like a cylinder below the head. That is your basic neck shape, remember it is just not sick too thin or too long. Then add in some details. Two lines should be drawn on each side of this cylinder, representing the front muscles.
Then, add a couple more lines which are faint so as to suggest the collarbones at the base of the neck. In the end, just keep with it! Neck- everyone has a different one; so take a look at various models and pictures for ideas.