Woo, the aspiring swordsman, one of the greatest anime characters ever! He's a bit simple. Working with outlines that aren't so noticeable, with other colors than just black, and shading even for minor details would improve it a lot. Shade doesn't always have to be black either. Practice makes perfect. As for the pirate logo, that looks perfect in vector format. Not the strawhat emblem, but a cool one regardless. Zoros own? Keep it going!
-cd-