On a drawing like this one for Roon, I'll start in a large sketchbook. In feeling out the pose and action, I often run out of room to finish the drawing so I'll scan what I have, print that out as a slightly smaller version, then finish the drawing out to roughly the appropriate size ratio with background and everything.
Then BACK to the scanner and back into photoshop where I deliberate placement and proportions, etc. Sometimes looking at the image on a computer screen helps me see little things that need to be tweaked - I'll adjust the size of a figure in the background or maybe bump the horizon line a tad - rotate a weapon a smidge so it isn't interfering with some other component of the composition - and so on. In the case of Roon, I did a little of all these things. I played around with whether I wanted Roon to be bigger or smaller in the frame according to how much of his whacky staff was going to be cropped off at the top and adjusted the building behind him this way and that to get it to feel right in the composition - all in hopes that I can get it all into a good, well-reading balance that makes for a potentially exciting painting.
You can see the final painting HERE on my art blog.
Oh, and the final painting is up for auction on Ebay through January 13th. Feel like owning a nice piece of original Magic artwork? Check it out HERE.