Oh my goodness! It's a robot creature! Well, not yet... but SOON!
Let's begin by drawing a circle for the chest. Next, draw a V-shape beneath that circle, and now you have the torso that everything will connect to. Try to pretend this is an action figure with ball joints for the head, shoulders and hips. Once you have that in your head, place some circles in there for those shapes. In this action pose, the arms will be up, so the shoulders are also up high on the torso. The hips are static, so they don't move from their position on the pelvis.
Draw curves to indicate the outer lines of the arms and legs. Keep the letter "B" in mind when drawing these. You can especially see the B-shape in the legs. Indicate the hand and feet, and then -- WHAT IS WITH THAT ARM?!
So apparently this guy is punching at us. Not very nice. Draw a big circle for hand placement, and attach it to the shoulder with a simple curve.
Whoa, wait -- what happened? That's a big jump, from Step 1 to Step 2, right?
After laying in those basic shapes from Step 1, I made a loose pencil sketch to figure out the shapes I want on this guy. It looks detailed, but it's not that hard. It's also extremely SMALL. I blew up the sketch for this tutorial, but the original drawing is only about 2.5 inches tall. The final image will be nearly 10 inches tall at 300 dpi, so there's a lot of work to do before we get there. The most important thing at this step is your MIND.
Once you have your basic skeleton structure, you can kind of shut your brain off and start doodling in shapes here and there. Since this is a robotic character, there will obviously be more hard angles than on a soft, human character. Keeping the three basic shapes in mind (circle, triangle, square), just go to town on this bad boy. Explore. Experiment. This is an original, mechanical creature thing. There are no real rules except that whatever looks right is right, and whatever looks wrong is wrong.
While I used some basic human anatomy for panels on the upper legs, everything else is just a mish-mash of random shapes layered on top of one another. The tricky part is trying to clean up this sketch and turning it into something presentable.
Here's where it starts to come together for real. All those loose, rough shapes need to be transformed into solid, geometric shapes. Since he's essentially a robot, use the Pen Tool to draw your straight lines and curves.
The methodology here is to move from foreground to background. That crazy hand is obviously the object closest to us, the viewer, so start there. Since those finger-claws are in the extreme foreground, use a fairly thick line while drawing.
When drawing something like this, try to keep in mind the scales on a dinosaur or dragon. You want these big, armored plates to overlap, especially working your way up the foreshortened arm and into the shoulder. One object in front of another. That's how you create depth and dimension.
As you move on to the body and the other limbs, shrink your line width a bit to show that these parts are further back in space than the hand. Since this is a robot, all the lines have to connect. It's the exact opposite of an organic creature, so all of these wacky shapes have to be clearly defined.
If you come across something you don't know how to outline (as often happens when working from a small sketch like this), simply the shape in your head. Try to turn it into something familiar, that you're more comfortable drawing. If you know how to draw a box, turn it into a box. If you have trouble drawing boxes, turn it into an egg-shape.
Once you've outlined most of the big shapes of the robot, you can go in and start adding all sorts of details. Before anything else, reduce your line width! If you start adding details with a thick line, the whole drawing will fall apart!
On any large machine, seems and panel lines are details that help show the size and scale of what you're drawing. Once you reach this detail stage, you really have to start thinking about three-dimensional shapes. It's these detail lines that make a circle look like a sphere, and make a diamond shape look like a pyramid shape. Since there are a lot of round shapes on this robot, pretend you're pulling a string across a ball. It's the same thinking as when you're drawing clothes on a human. In that case, the wrinkles wrap around the body. In THIS case, the panel lines and seems wrap around metal plates.
At this point, try to close up any unfinished areas so that there are no open shapes. Everything should be enclosed.
EXTREME DETAILS. *ahem*
Cracks, serial numbers, scratches, and other minor details help to add scale and realism to your robot creation. As you can see, I decided to "black out" some areas of the drawing to break up the monotonous white shapes. I added more panel lines and even drew some details within the black shapes. At this stage, feel free to use reference material. Look at a battleship or rocket and borrow details from those machines to increase the realism of your drawing and give your viewers something extra to look at. These details also give you a chance to dress up areas of the drawing that should have been better though out (such as those overly-simplistic feet!).
The only thing left to add is a bit of propulsion. These blasts of flame transform this from just a "Here I am" pose to an action pose. At least, that's the idea. I haven't designed thrusters for this guy, but we'll assume he has two thrusters on his back. That means two burts of flame/energy. Just use the pen tool and keep mixing curves with straight zap lines.
The final product in black. I'm actually pleased with how this turned out. The computer is definitely useful when drawing anything that requires precise curves and lots of geometric shapes. I suppose you could even achieve similar results using something as basic as MS Paint and the line tool. Now go and color it up!