How do I create a 'cut out' type effect?

So I'm busy with the main wall cabinet behind the counter.  The problem that i have now is that in the real room, the shapes/panels are a 'cut out' rather than an 'add on', so they're inset rather than sticking out.  They also have that wee cut out of each corner.  I've figured how to do that with a hole punch but I can't figure how to do the inset panels cleanly.  Any ideas?