Penciling the final lines lightly helps a lot before inking; using technical pens keeps the lines fairly consistent, too. My minor mistakes don't always turn into other features...90% of the time
; bigger ones, though, are usually undone with white-out or similar media. Trying to raise that percentage, you know?
With pen and ink, practice and learning techniques are pretty much all it really takes; I need to work on increasing my line drawing speed so that there is less jitter on long strokes.
I actually haven't decided if this mech is piloted or not, haha. But I do have a soft spot for autonomous, sentient machines.