I'm new to Blender, so I feel I must be missing something. I'm modelling something that's bound for a 3D printer and I need to cut some specifically shaped (and spaced) holes in it.
I've tried knife, knife project, bisect, and boolean modifiers, all with limited success. Knife (and knife project) were particularly infuriating, as they worked great on the outside of the object, but when I needed to cut the holes on the interior they failed miserably. It seemed my only options were to cut nothing or all the way through from the current view. I finally got the surface I want, but only after hacking the faces to death with the knife and merging edge loops a couple of times. It left the mesh rather a mess...
Is there any better way to do this? What about cleaning up the mesh a little?
Desired result finally:
Ugly, underlying topology: