Let's focus on a completely different part of the world, but a part that is still intrinsically linked to the stories of steampunk piracy and adventure. We'll start detailing the Old World, particularly the Empire of the Sun and it's neighbouring lands.
First we'll zoom in on the area that's going to be detailed.
I crop this section of the map, because it nicely lines up with the grid sections I've already drawn, it also doesn't go too far into the polar regions of the planet so don't need to worry too much about distortion of the geography.
Once the section has been cropped, I multiply it's size by 400%. That's a pretty arbitrary number, but the larger it is the more memory the file takes up, ad the more detailed the "difference cloud" maps will be when I generate them. I like detail, but big files can be unwieldy. So it's a case of balancing the amount of detail I want with the amount of memory I can afford to use. 400% in this case is a reasonable balance.
Now I run the "clouds" filter, and apply the "difference clouds" a couple of times until I end up with something beautifully convoluted.
Turning the opacity on this layer down to about 40%, I end up with a map that looks like this.
The pale parts of the map give me a pretty good idea of where mountain ranges will be in this part of the world. Roughly the area designated as the "Empire of the Sun" is mountainous, while there are flatlands stretching across the peninsula and a mountain range on the western coast. I can work with that. There are also some interesting mountain ranges to the south-east of the map, in the area previously defined as "The Sacred Lands".
The reason I've toned this map down to 40% is because I want the original map layer to form the general coastlines, while this layer tweaks them ever so slightly.
I have noticed one thing that's a bit of a concern though. Some of the mountain ranges occur where I think it would make more sense to have flattened land. So I create another layer to spray some dark patches where I want the hills suppressed.
I turn this "suppression layer" down to 30% opacity, turn the difference clouds beneath it down to 40%, and use the black and white threshold map layer beneath that. I perform a "copy merged" operation on this map, and apply a new threshold at the 128 level. At this stage, I have a result like this.
Not bad, there are even a few black scribbles that could easily be wide parts of rivers on the map. I turn the threshold down a bit, just to 127. There are a few too many of these "rivers" and this eliminates a few of them.
I apply this threshold map as a layer over the top of everything with a "darken" mode.
Then in a new layer I start drawing a lot of borders to indicate kingdoms, baronies, states, provinces, and all sorts of small geographic boundaries. I make sure these follow the pale ridge lines and the dark valley riverways, these form the typical borders that you'd find in a medieval world (or a world emerging into it's own age of enlightenment). A nation will be formed from a few of these provincial areas.
I also try to make sure there are different sizes of these provincial areas, working on the assumption that they traditionally had roughly equal population (though this might not be the case now). Thus, more fertile areas capable of sustaining higher populations are more sought after, and thus their borders will be encroached upon. Desolate lands have wider range because they are less threatened by their neighbours.
I end up with a map like this.
Then in another new layer, I apply colour to the different nations of allied provincial states. One for the Empire, one for Ogland, one for Nydia, one for the Sacred Lands, and one for a loose affiliate of states to the southwest (who will form a vague Nordic cultural grouping).
This starts giving me ideas about where to take the Old World in the setting.