lots of us don't bother with much of the math when designing models... the "TLAR" method generally works after you've built 3 or 4 kits. (and you need to build at least 3 kits before trying to design one...) You'll get a "feel" for how the structure should look, and what shapes make decent airfoils. Also after flying a few planes of differing design, you'll get an idea of what wing planforms (the shape when looking straight down on the aircraft) are best for which purpose.

The biggest exception... I think Curmudgeon Paul has all the equations memorized. [img]i/expressions/face-icon-small-happy.gif[/img]