Alright, in the interest of promoting some postings and discussion; here is a topic I don't think has been addressed.
We all know that furniture scale to human dimensions is important, particularly for tables, chairs and desks and that various rules of thumb have been developed over the years to address how to scale those objects for the human form.
My question relates to scaling furniture for a room. A piece that looks good in a magazine or other setting may be way out of scale in a woodworker's intended application (either too large or too small for a room). In the past, I have resorted to mock-ups and tape outlines to help determine scale and found that the tape outline is only a poor indicator of how things will look -- the mockup is a much higher fidelity measure, but takes more time. I have also been burned by building something from plans that later look too large in my setting. Are there any good rules of thumb for what looks good in a particular setting other than a mockup?