I don't know if you intend to represent your map as spherical projection.
But if you do, I'd recommend to do the work in equirectangular projection first (2 wide, 1 high). This is the easiest way to do a map if you want to get the right coordinates quickly and accurately.
Only when it's done you project the result on a sphere. The coordinates are still correct and the shapes look naturally what is rarely the case when one tries to map on a sphere directly - we simply can't draw correctly and naturally on a sphere.
Even if you have a first sketch on a sphere because you want the relative areas to be in certain proportions, it is better to reproject the sketch on an equirectangular map, do the whole detail work there and then finish by projecting the finished map on a sphere again.