So! I had this little idea of making derpy-faced cat. After 10 minutes with inkscape, I ended up with this...I'd say it's good enough but I've yet much to learn.
As far as inkscape goes, It's love and hate relationship. I love it because it's pretty decent and free, but I also hate it because it does have tendency to make some things needlessly complicated. As for it's usage and tips for new users, I can recommend you this website. It's all about using the polygon tool, converting objects to paths, applying logical operations to those paths and so on.
I usually use Inkscape, but for the drawing I'm doing currently I'm using GIMP due to a derp up while creating the original file... and already I'm becoming addicted. One of the major things I didn't like about Inkscape is that you either had no pointy corners at all or your lines ended up really jagged upon zooming in, the main issue is that's more to do with the fact that Inkscape is vector rather than just a straight off image editor, but please just let me make pointy spaceships without making all my lines look like they are furiously trying to stick to a grid!