Tweaknation: Space Squad!!
I think it's important to take stock of your improvements as an artist. To look back and compare your skills of a couple of years ago to your current skill level. With that in mind, I think my 2013 artist self has improved over my 2010...2009..artist self.
An important skill for any artist is the skill of observation. And I've been busily observing my cats; which they love because...ATTENTION! Cats love the attention! Also, anatomy. Anatomy skills have greatly improved. Human and critters. As well as other areas. I just think I'm a better artist now than I was a couple of years ago.
Also helps in having friends who were Art Directors. A good friend (and someone who's mentored me in this business of art), took a look at my old and new portfolios and provided me with a whole lotta tips. I made copious mental notes and have been taking those and repainting old pieces (old pieces that matter in the portfolio) when I've had the time.
I'll post them here when I've completed them. Here's the first one, Space Squad! As I've mentioned: cat anatomy, human anatomy, composition sense and the all-useful third person observation, in the form of an Art Director's eye: and this is the result.