as someone who usually just looks for lower class people in paintings (and they dont show up much in paintings at all, very rarely in religious ones), i don't look at the 'religious' paintings too often. but usually, these are done with more attention to detail, and it would be nice to know what kind of details might be useful.

lets look at some paintings here for examples:
by Petrus Christus,
http://www.kfki.hu/~arthp/html/c/christus/

first, St. Eligius in his Workshop, a nominally religious theme.
I presume that St. Eligius is the one sitting down, and the other two are, what, customers? is this saint likely to be wearing stylized clothing? The other two at casual glance look all right for 1450 to my eye, and there's all kinds of nifty doodads strewn about, which I presume are all fine.

OTOH, look at the Lamentation (the one currently in Brussels). These people all look pretty suspect as dressed in a non-contemporary fashion to me. But, it would be handy if I knew that the clearly visible side lacing on the one on the left (who is that? Mary Magdalen?) was a contemporary detail in an otherwise stylized garment.

Anyone have any insights on this subject in general (not to be confined necessarily to these two paintings)?