How they stroke there paintbrush and how light and dark the color is or how thick it looks and how realistic it is and mostly what is the main reason or a hidden message about the painting.
Look back at a time where you really screwed things up, but you learned something
then basically just tell them a time where you screwed up and survived
(you could just take the time that you messed up and make up a lesson you learned, you don't actually have to learn it, it just has to sound believable)
This is incorrect. Gouache painting is very very similar to watercolours, so much so that the two can be used together. It is an opaque method of painting.