I agree with BAX. I've done a good amount of "TLARing" over the years and the basic ratios that BAX has spelled out DO in fact work amazingly well, and constitute the general layout of 95% of the r/c models out there. There's always a few that go outside the box, but by and large...they don't deviate far from the tried and true.

You can skip a great deal of the secret science, and instead concentrate your effort on building the model STRAIGHTER and LIGHTER and that will make even the most homely looking design fly incredibly well.