Getting consistent/clean brush strikes in GIMP

[Broadhead]

Hey everyone, quick question for people like me working in GIMP. What brush and settings should I use to get strokes that are the same as the one this guy (Levodoom) uses for his ridge lines and rivers? He even seems to apply some sort of light outer glow around them. I've been playing around with brushes for a day or two but can't recreate the thickness/consistency or result of these brush lines.

[Tiana]

I don't use Gimp but my guess is, the artist duplicated their lines and put a blur on the one underneath, then set that to something like screen. Then on a layer above everything else, with an airbrush, they dabbed on some glow, probably also on a screen layer. The consistency is just practice, and sometimes, stabilizer tools like Lazy Nezumi.

[XCali]

I use gimp, the consisitancy and thickness makes me think it's just him using a drawing tablet, but it's possible with a mouse. BUT the importance here is, he either used an eraser on LOW opacity to fade the lines, OR another possibility is he used brush settings, (That tab with the blue arrow) to add a fade to his brush strokes at the end or the beginning

The soft outer glow, can be simple as Righ clicking Alpha to selection on the river line art and then creating a layer below that layer. Grow the selection by 1 and then throw in a color of your choosing, then add a guassian blur to that layer to get your desired effect. (Play with the layer's opacity if you need)

Hope this helps. That's way's I can think of doing it in gimp.

But, the way I'd do the rivers is to add highlights and soft shadows to shore edges to make them pop

[Broadhead]

This is very helpful, thank you