shiNIN: So basically you can't create or change a thumbnail after you have created the thread?
About hands, erm. I'd say that there are a few good books on drawing hands that could teach you more expertly than I can. Anyway here is how I usually tackle hands, in some order or a another:
--- Line of action. Usually hand gestures are driven by some motivation, like piking up a bottle cork, or punching laziness in the face. I usually start by drawing a simple line to show the direction of the action and to help to get the overall proportions. One finger is usually a lead actor that tells the most about the action. I indicate big forms and their direction really basically with looooose ovalish and boxish shapes, not surrounding the complete form, just indicating it. I give sometimes give the fingertips a common line of action.
--- Masses. Give bulk, mass and indicate the big planes somewhat. I really like this stage for some reason . I usually indicate which mass is in front of another by basically wrapping some lines along/around the form, often going heavier where forms connect and go onto of each other.
---Joints. I usually represent them at first as quick ball shapes and then try to go cylindric boxy on them. Funny words, but trying to indicate direction and from.
---Something. I find that being loose and drawing with keeping the pen on the paper for looong periods at a time makes it easier to draw, personally. Same in hands, when I'm loose it comes out more naturally and when I'm tense chicken scratching happens (going over the same line a million times).
--->>> Relax, a bad drawing Is not going to bite you. Think of the action of the hand and the masses. Go from big to small. Sometimes i just draw all the fingers as one form and separate them from that.
I recorded some process clips of drawing hands in photoshop. I usually take max 3min/hand, the average is about on minute. Haven't actually tried a long drawing where I'd really get into rendering with the hand.
Most of my drawings are down from observation, at least for now. So most often i draw my left hand, but there's one right hand in my previous hand drawings. Drew that with my left hand and I like it more than the ones i did with my right hand >_<. I don't know whether to laugh or cry. I'll laugh.
I tried to do a video tutorial on hands, but my digitally drawn hands are just dreadful. Well I have to think of something. The recording thing isn't a problem, just that I draw better traditionally. Practice time >:3.
Hope that helps somewhat. Personally I find it really difficult to implement advice and studies to my own work.. Don't know if I'm doing it wrong or just a lack of practice at doing it. Maybe its the expectation of instant results.
anyway, stuff, self-portrait with unintentional minilips and a weird ear, experiments, fun, and dreadful digitally drawn hands, -enjoy :3