Does the background recede far enough?

[Timothy C. Tyler]

I think Marvin's thoughts were most useful to your question because you are not really dealing with aerial perspective so much as slight depth of field. I think of Schmid and Dean Cromwell-both use (or used) line and design to help create depth as much as intensity etc. I feel some carefull softening of lines where those intersect your figure will help you greatly. Sacrifice everything for the figure.