>>5807447I personally don't even dilute my flow aid (I use the one from Liquitex).
I just put a few drops on a plate, then I dip my brush into my paint (I use Mr. Hobby Aqueous Color, which is highly pigmented but feels very watery) and then dip it into the little flow aid pool.
Mix it and you are good to go.
For a while I mostly bought Pro Arte Connoisseur Series 100 brushes, but that got too expensive since I had to import them from the UK (can't get them in Germany).
I nowadays just use the Games Workshop brushes, which I need to replace more often but are at least easier to get.
Regarding different results when people use same materials: there is a big difference in handling these materials, and acrylic paint is not always the same just because it shares a type.
Not to mention how differently people layer, there are some people who paint the lines first and then blush too.
Pencils are unfortunately always grainy, no matter what.
I personally didn't thought they were easier to handle either, for me the brush always felt more natural, but it's of course less messy.
For me the most important is a mixture of brush shape (short, with a wide base but a very thin tip, basically a /\ shape) and paint viscosity.
I also paint in several layers, i.e. I first paint very light lashes, seal that, and then darken the base of the lashes.
That way the tip stays light.
Else it's really just practicing.
Making nice, fine lines is unfortunately something you really need to learn, no matter how much theory you know and tutorials you read.
Best is to learn painting lines on a headcap, again and again.