I've recently been using the winter weather and new studio as an opportunity to focus and reflect on my studio practice and work up a few pieces from my plein air studies. I should be able to post up some shots fairly soon. I think it's useful to balance studio work with painting outdoors as they can be quite different experiences. Outside, you end up getting absorbed in the motif and the moment and (for me anyway) the empahsis tends to be on observing the subject and translating into paint. It's important to have an idea or 'spark' though so that it's not just an exercise in copying what's there. Otherwise the results will sometimes be quite dull.
I've been reading a quite brilliant book by John F Carlson recently (http://www.amazon.co.uk/Guide-Landscape-Painting-J-F-Carlson/dp/0486229270/ref=pd_ys_iyr_img) and in it he says:
"We must not train our eyes to copy tone for tone but think of the bearing of such colors and harmonies upon the main idea of our picture"
This perhaps seems obvious but it can be easily forgotten when working on a painting, especially in the heat of the moment on location. Studio practice always seems to be more reflective wheras plein air painting is more instinctive. However, I think it is the quality of thinking that underpins the quality of the outcome in both cases. Technique almost becomes secondary, a tool to be used when called upon. Of course, good technique is important but I don't think it should be the entire story behind a painting. If the right thoughts can inform the right decisions then a better outcome is much more likely.