Overprocessing was mentioned by more than one responder. Overprocessing is so easy to do... it's a bit of the Tim Taylor mentality of "more...", after all if a little is good a lot must be very good, right? :o)
This past weekend I did a shoot of a young couple and found myself falling into the overprocessing trap. The background was predominantly a lovely autumn mix of oranges and golds with a smattering of green. It's sad, but it didn't take me long to get tired of the background (even though in the majority of the images the bokeh was perfect) so what did I do? Well, start layering actions on actions, tweaking every little thing then topping it all with at least one texture, of course.
As I was processing this evening I consciously held back, looking at each image critically and asking myself, "what does this particular image really need?" It's rather interesting that even with the intentional processing I had to fight the urge to keep doing "more."
Here are a few examples of what I ended up with this evening. Any suggestions or advice?