Currently I am using Paint tool sai to draw, but i cant seem to make my lineart look fluid and natural, and also look like a single outline. i always have little hairs sticking out from the lines and i dont know how to get around that.something ive noticed online is that some people can make the lineart of their drawings perfectly, but it still looks natural. im not sure if you know what i mean, but if anyone can point me in the direction of how to do that, i'd greatly appreciate it.
I did the lineart on my last piece using the brush tool (no lineart layer) and I loved it. It's WAY easier to get a nice line than it is with the lineart tool. Other than that I just tried to get the lines down in one sweeping motion. Takes a bit of practice.
Create a lineart layer and use the pen tool. I can't remember exactly how to do this, given it's been ages since I used SAI, but I'm sure if you google it you can find out.