Ok now, here is the final step to making a basic Transformer pic. After you have gone over all the lines you want to keep in ink, begin to erase, erase, erase (hate this part, a lot of work).
You should be left with the above pick. Nice enough on its own, but it doesn't jump out at you.
What you need to do is out line the major structures or body parts (like leg or chest). Do this with a pen that flows heavier or a thin marker. Not to thick 'cause you may loose some detail. Do not over do your heavy lines, keep to only major parts otherwise you'll be left with a pic full of heavy lines that doesn't jump out at you, but rather confuse you. It should look like the bottom pic. Feel free to add seams, dents, scratches, or dots for rivets and such with your thinner pen.
If you want review:
Part one: Blocked out (Basic Shapes)[link]
Part Two: Details (sketch out your character) [link]
Part Three: Clean up & Ink (pretty explanatory