Step 4.
I'm left handed. I can draw freehand lines that go from top left to bottom right but, particularly on a computer where you can't rotate the page on your table, I find it impossible to do them the other way round. That's where flipping the image comes in handy. By flipping the image you sometimes suddenly spot fundamental problems with the drawing that you hadn't already seen. You flip by going Image> Rotate canvas> Flip horizontal. Similarly you can flip vertical or rotate in increments of 90 degrees. (Working in line you should never rotate arbitrarily or you get lines with fuzzy gray edges. I think I forgot to mention at the beginning that I'm only drawing with the un-anti-aliased Pencil and Eraser tools so that every pixel is either black or white.
Having said that what I'm about to say contradicts that. In the step you see before you I've decided that her right upper arm could do with being a bit longer. (Flipped it has become her left arm.) I've drawn a lasso round the bit I want to move thus selecting it. I always hide the "marching ants" by going Command-H. I then go Edit> Free transform (Command-T) and I get a rectangular box with movable points on it. I can resize the selected pit of the image or do anything I like with it. In this case I want to rotate it. I move the fulcrum or pivot or whatever you'd like to call it up to her wrist and rotate the rest of the arm away from the elbow. When I hit Enter the box goes away and the arm is in its new position. I now have to deselect (Command-D) and I can touch up the gap by hand. The thing about this new bit of arm is that it is now anti-aliased, ie. it has blurry gray edges to its pixels. At this stage of the work, before I start inking this doesn't particularly matter because it'll ultimately be discarded. But I would never do this during the inking process.
Step 4.
