I'm slowly making progress on my postcard project for Facebook friends; I've finished six of the first series of 15 and am now working on the seventh. The first five were hackish copies of other artwork done by actual artists; the sixth was my first attempt at an original work. I used a photo of a Chinese aircraft carrier for reference to get the perspective, and then used a lineart concept drawing.
Main issues -- the bow is a mess, and I need a ton of practice with getting line weight correct. I tried a few things with this, but there is clearly a lot more for me to try and learn. And I got lazy and sloppy with the water and the logo, too, but that's obviously fixable by, y'know, not being lazy and sloppy.
Fun project, and hopefully by the time I finish the 26 or 27 of these I still have left to do for people, I'll start seeing some real improvement. I'm trying to pick projects with an eye toward subjects with specific things I'd like to try and work on, as well.