In blender I just use hardops to create bevels to achieve the effect you're talking about. Subdivision is usually not a good idea with hardsurface props.
Thank's, Ged! Yea I've got a couple of these illustrative type images to finish up then I plan on getting back to some of these hardsurface designs....
Polycount's Weekly Hardsurface Challenge is an invaluable source of modeling inspiration and shapes for practice. Do a dozen or two of them and you'll be a better modeler in no time.