Captain Character: Development of Expression Sheets

(Early expression sheet for my character)

There are many ways in which character can be conveyed through body language, though none is more universal than facial expression. In order for my character to display a full range of emotion I need create an expression sheet that showcases a wide variety of facial expressions, for everything from anger to joy. 

Here I have created a series of heads of my character, all based around the same template. The differences are subtle and upon reflection, barely substantial. The thought process behind this was that the facial structure is less caricatured and more based off a realistic face, though with some exaggeration, hence the slighter less pronounced changes in the face. However, I'll admit that this effect is not fully achieved and comes across primarily as lazy and ill thought out. 

As the mouth opens, the head does not squash and stretch, hence less is expressed through facial expression and from a distance, the heads don't look all that different. Almost robotic in their uniformity, when they should be vastly different to convey vastly differing states of emotion. To amend this, when further developing my expression sheets I will seek to incorporate more gestures and variety in composition to give my character more 'character'.