Sketching nature is best of the best for studying and improving your art skills. Starting to fill my new mini sketchbook. For sketch I use Derwent Graphik multiliners and Pilot G-Tec-C4 gel pen. Derwent Graphik series multiliners not so good, due to the fact that the ink which they use are not waterproof and can easily smudge with your hand or an eraser even after a long time after drawing was finished, we plan to make a short review soon. Thank you @beritwetterstad for the photo ref!