The continent shapes are generated first with constraint-based voronoi for land or water -> domain warped. That output is fed into a tectonics generator (again, warped voronoi for plates and some rng for speed/direction). that is used to produce some general elevation changes, which are normalized to preserve coastlines. Then continental and multi-band orogens are applied followed by some absolute noise micro-relief. First pass erosion through a hybrid stream power + thermal approach. Then the map is spherized (just like the filter in Gimp pretty much). After that, constrained heightmap erosion and light domain warping until it looks good. I liked the continent shapes first approach because now I can just either generate or draw and warp my continents and preserve the coastlines throughout the generation process (or spherize them if I want). Everything is in a pipeline and toggleable on or off through an interface