Hi jki - it looks like you are trying to manually build the connection surfaces. Don't do it that way - you need to use filleting to generate those connection pieces for you and filleting will do the work to make its blending pieces be smooth to the other surfaces.
It's quite difficult to get the same result as filleting in a manual construction type method.
Basically you want to focus your initial work on building just the larger sheets of your object, and not focus initially on any of the more highly curved areas. Where you have a highly curved area, that is a transition in between 2 larger forms and you want the larger forms to be modeled separately and the transition comes from a fillet.
