I think that a lot of the reason Jarvis has become so human is because Tony treats him like he’s human. Tony talks to Jarvis in a very colloquial way. He says “you up?” when he knows damn well that Jarvis is operational. He says “throw a little hot-rod red in there” instead of “paint components x, y, and z with red paint #20.” Tony treats all his machinery like that—Dummy and You, especially—and Jarvis is no exception.
Jarvis has become much more human since Iron Man 1. He actually displayed emotions in Iron Man 3—specifically when he feared for Tony’s life, his voice sounded terribly frightened, and in instances like the second gif where he said “I need to sleep” and not “My battery is depleted.” Jarvis has grown and changed, as any self-aware creature does. He has become human because he is treated as such.
Just use any old toothbrush. I used to use the ones that my dentist would give me after a visit, just because those were kind of cheap and I wouldn’t actually use them anyways.
I use acrylic for flicking and highlights because watercolour-whites tend to fade when they dry.
Also, remember to keep your hands clean, because nothing’s worse than smudging graphite into your watercolours and then unable to get it out.
Try to avoid black and white when possible. They tend to dull the colours and it loses that watercolouring lustre.
Since I started watercolouring again for my daily sketches, I’ve gotten a lot of asks/dA notes on if I could give a tutorial on watercolouring and also more specific questions that overlapped each other, so I decided to do a semi guide/tips/answering thing.
I actually started watercolouring before I went into digital medium, so I have a bit of personal experience, but I am essentially self-taught when it comes to watercolouring since there weren’t a lot of watercolour tutorials online back then to begin with, so I cannot promise that these are the absolute correct way of doing things.