I have two ways. If it's for a sketch piece like this, I'll use Flash or Harmony. Because Ii can work quickly and the lines look clean at a distance. lol For actual clean up, I use Photoshop. usually at 300 or 600 DPI and a canvas of no less than 3000 px. Also, that's an awesome character haha
Hey! How's it going? What kind of character work are you looking for? Action poses Standing poses turn sheets? Here is some of my work I maybe able to help. Check out my profile and Feel free to shoot me a note or email me at graphic.arts@yahoo.com