Hi! So I'm not really a realistic artist, I make more cutesy art.
Here's a tip:
When you are making an Oekaki, on the right in the little box where you choose the opacity and whatnot, the last bar says smoothing. If you make the level of smoothing higher, your lines will be smoother. Don't fill up the bar all the way, though, or it will go very slowly and take a long time to make one line. I reccomend filling it up around 90-95%

