I love post its! i carry it everywhere I go. Last week I headed to the national park near my home and sketched every tree and shrubbery. At first I wasn't able to draw trees that well. I always wondered how i could make tress, 'look' like trees. i took reference from Osamu Tezuka. I loved how he used closely placed contour lines to give the effect of the beautiful textures of trees trunks. I used that method and to my surprise, my trees don't look weird anymore!