What I learned about this feature, is that randomness sometimes is not bad.
Feel FREE to do it without questioning too much, good results can appear even without thinking it. Do not practice a desire shape separately, start with your final part at once, and enjoy improvisation.
More precisely to your question, start with a similar shape and use subdivisions and only FEW (if not zero) extrusions to approximate your base shape to the final shape. Subdivisions creates "straight" surfaces, so you can use it as model technique. Then, you can add detail by extruding some faces, notice that this operation will straight more your initial surfaces.
