So, n00b here. Hi. :3

Long story short, I've been in a kind of weird geopolitical simulation forum game/thing for several years by now (name's NationStates), even though I took a lot of breaks here and there for a variety of reasons. I've had no issue emulating the Wikipedia style for the simpler maps, since it's a matter of colour and not much else, but months of attempts at a semi-realistic physical map more or less went nowhere, even while closely following Gimp and Wilbur tutorials. I suppose the problem here, is that I've found no way to go from here (image screencapped from Wikipedia)

Screenshot 2024-06-22 193711.png

To here (image screencapped from the same Wikipedia page of the previous one)

Screenshot 2024-06-22 193933.png

Basically, if I found a way to emulate an impression of tridimensional altitude/height (quite apparent underneath the colour scheme) I'd be more than halfway done, since I've already worked out where the various physical features are supposed to be. Right now, my attempts look too flat, for a convincing Wikipedia-esque map. Any advice?