Time for me bite the bullet and actually post something, I suppose - I've been lurking (and hopefully absorbing ideas and advice) for far too long.
Welcome to Kerandia, a flooded world for a D&D (4e) campaign.
The basic pretext for this world is that war between Teiflings and Dragonborn came to an end 1232 years ago when each of the sides were tricked into performing a ritual which would drown their enemy's armies. The rituals were actually being coordinated by a Bad Entity and had the effect of opening a gate to an elemental realm of water, flooding most of the world and displacing survivors into scattered communities (to achieve the "points of light" effect together with explaining the high racial mix in survivor communities).
I wanted some relatively large landmasses for the lower levels of the campaign before my brave heroes buckle their swashes and take to the high seas for mid-level adventures. They'll start moving on to exploring a network of teleportation circles towards the end of the campaign, the successful conclusion of which may well see them restoring the world to its pre-flood configuration.
I played with settings in Fractal Terrains for a while until I created a world which featured a pleasing arrangements of islands and then traced this map in Campaign Cartographer 3. I've adapted the overland b/w style (quite a lot for some layers) and am deliberately keeping colour use to a minimum.
I know I've made the settlement icons too small (yes, there are 8 settlements on the map, honest!) but that's easily remedied. The bigger issue is what to do about the hills. At the moment, they're denoted by a brownish contour line - I didn't want to use icons for the hills on the campaign-level map, reserving icon use to show the mountains at this scale. Any suggestions for improving how these areas appear would be very much appreciated.
Welcome to the Cartographers' Guild Emrys, and have some reputation
The coastlines and color scheme of your map look pretty nice. Perhaps the lables could be moved so that they are directly over the areas they're naming, though.
As for your hill dilemma, I don't quite understand what the problem is. Hills either are too insignificant for this scale, in which case they need not be represented at all, -or- they are significant enough for the scale, in which case you might as well represent them with icons.
Consider that map icons don't have to match actual terrain features accurately. A cluster of five mountains on a map, for example, doesn't have to mean that there actually are five peaks at those exact locations - it could simply be taken as a symbolic way to say "here be mountains". Just like a bunch of tree symbols can be used to indicate a forest.
I agree with Ghostman. Either just leave the hills out - since nearly all of them surround the mountains and all the mountains are ringed with hilly areas, the mountains pretty much cover the hill areas if you just assume them - or go ahead with icons.
It's occurred to me that all of the land is - according to the background - what was formerly high ground and so hills should, therefore, be the default terrain.
I've replaced the various settlement icons with a single, simple and slightly larger icon - hopefully these are now a lot clearer. I also tried labelling the settlements but think I'll leave them unlabelled on the overall map - there'll be plenty of labels once I start on the regional maps. I've attached versions with and without settlement labels.
Now all I have to do is decide where the campaign will start (to determine which region is the first to be mapped in more detail). At the moment my money's on Caer Dynvant, to keep things central.