I have been building kits for a while and have always been interested in scratch-building. I have always wanted an F8 Bearcat and a T-28 Trojan, but have never been able to find a kit or plans in the size I want. So I figured I could go with three views, and design my own basic structure. I have a pretty good idea of how to do this except for on some parts such as wing rib shape and fuselage former shape. What are some techniques you guys use to make these? What else should I know about things like horizontal and vertical stabilizer enlargements in order to make the plane a better flier than a perfectly scale plane? I want my plane to fit a .25 engine, and be just a good sport flyer. Any help you can give would be very helpful.

Both the Jerry Bates and Nick Ziroli version of the Bearcat are available here.
http://www.precisioncutkits.com/instock.html

Yours will be smaller, and you could simply use sheet balsa for the tail surfaces. Or, if you want it to appear more scale, build them up like a "mini-Ziroli" kit.

The Bearcat has some landing gear "issues" you may want to check out, if you haven't already.