look closely at the lighter green lines (above) which I didn't draw with enough patience. You can draw with the necessary patience or "Hide" the flaws with another icon.

Keep in mind that deeper colors on the bottom and lighter colors on top when choosing your land features help with the feeling of depth.

In Sue Richards' annual Darklands you will, in my opinion, find the best solution to this situation. Since unfortunately other styles do not have, like this, "north-oriented" cliffs.

As you did with land features on the map, you will need a lot of patience to cover the finer lines with the land feature you choose.

had same problem here time ago, Ralf saved me with same advice. Now i never select black as text color, always a dark grey and never happened again.

https://www.youtube.com/watch?v=B8Fvz98lJ7Q&t=201s

Maybe this video will help something. For me, he was absolutely essential.