I decided to drop my last WIP as I grew more and more discontent with it. Also I had a lot of other stuff to do at that time. I restarted the whole project and created the following map-concept.
This time I decided to draw landmasses first and then tectonic plates. In my last project I did it the other way around and tried to draw the landmasses according to the tectnonic plates ... which in the end lead to several landmass concepts that I weren't really happy with.
This time I started with the landmasses and added the tectonic plates after that so they will help me to locate meaningful mountain ranges and stuff in the future.
For the coastlines I used many segments of real earth maps that totally rearranged.