Here's a cool thing I did and I think everybody should do once, just for the fun of it.
When I was 7 in 1984, I had a group of "Super-Trained-Soldiers" called "TEX PATROL". Of course, based mostly on the G.I.Joe characters... I used to make comic books of the team as good as I could. It lasted 3 issues. Here's the cover of the #3.
1984
Then, 13 years later, when I was 20, I did the same drawing again. Just to see how I had evolved. I didn't change anything, I chose to stick to the concept drawing of that 7yo kid.
1997
Well, when I was 27, in 2004 I did it again. Surely there was a huge difference between them 3, and I think it's a very interesting way to capture the evolving process of my drawings in spaces of 10 years. The second one took a little longer, I shoul've done it in 1994 but I'll try to make the next one in 2014, and the chronology will be a little better.
2004
Why don't you do the same? You just havo to redo a drawing from 10 years ago and make an appointment with yourself to redo the same drawing again in 10 years. C'mon... It's so EASY!