Directing the Viewer's Gaze -

smart artists make choices....and covering everything evenly with detail is not really making a choice. - mark kennedy

There are various ways to do this, in this post, however, I am concentrating on Balancing the Level of Detail:

It's always a challenge to get the viewer's eye to go to the part of a drawing (or painting) that is exactly where we want them to look. And putting detail where you want to attract the eye is a good, foolproof trick. And so, for that to work, the areas where you don't want the audience to look need to be blank, or at least have less detail than the areas where you want them to look.  The opposite of this can also be used. If there is an overload of detail, the eye will be drawn to a place of rest.

Jake  Parker

" It seems that as a general rule, contrast is a key to creating works of art that are interesting to look at, and of course a contrast is created when you have blank spaces against areas of detail, as opposed to a piece of art that is all detail, or a piece that is all blank open areas."

Also remember SMALL, MEDIUM, LARGE and the Gestalt Principle. If everything carries equal weight (in size, value, or detail) Then the brain is unable to organize what it is seeing - Your audience won't know where they are supposed to look or what part of the design is the most important.

CAKE AND FROSTING: Character designs follow a hierarchy: you grab the reader’s attention with the most essential information and then invite them to investigate the details.  If important elements of your design are only evident in the details, then it needs to be reworked.  If your character is not completely distinguishable in silhouette, it needs to be reworked.  Detail should always radiate from the core theme.  

For more, go to Mark Kennedy's post on DETAIL BALANCE

Jake Parker Demo - http://mrjakeparker.com/2012/10/03/inktober-day-3-2/