1. Basically cut off the pixel joining them so that the lines are joined diagonally (not in all cases, but most). 2. Skin is always hard, my advise to you is too look in the mirror or at other peoples and study it (don't stare and random people or you might get like beat up or something).. but the colour changes between light and shade and pretty drastic but there are colours inbetween that blend them in. 3. See #2. 4. Gradual shades, no drastic differences in light and shade, pay attention to the form of whatever is underneath the clothes and add that to the shading.. also don't forget creases and possibly dirt depending on what it's like. 5. See #4. 6. Very different to the others, Metal armour tends to have a very shiny surface, so its very light where the light is coming from, then goes straight to normal, then the shade forms most of the shape of the armour. 7. See #6. Any other questions just ask :P