To start with we need an underlying mesh to which we’ll add our details. Because I’m going for a spherical space station I’m using a simple Sphere ZTool, but you can use any shape you wish, and include sculpting details if you need to.
Give it another division to make it as smooth as you want, but not so dense as it becomes unmanageable. Get your base, draw it on the canvas and then hit T to make it editable.
Try clicking the Material swatch to pick something more suited to your intended use.