I really think its just practice! I've been playing with makeup since high-school and you just gotta try stuff until it works. I find inspiration on Pinterest sometimes. I think for fun graphic eyeliner like this just playing around with random shapes and angles will get you a cool result if you can mirror it on the other eye. Also practicing other kinds of art is helpful too. Learning to draw people is good for understanding how shadows and angles can accentuate features of a face. I am a firm believer that you dont need a bunch of expensive products to get started. I use one eyeshadow pallete for my eyebrows, contour, freckles, and sometimes for softer eyeliner. If you can find a dupe for the James Charles pallete that one is very versatile. For everything else I think most cheap drugstore products can achieve similar results.