RC biplane Baby Blender V2 is a good choice for those who are already comfortable with flying on aircraft models. Just download the blueprints and build this plane.
The plane is supposed to be more demanding than typical RC trainer, but still manageable by anyone who can perform most of the basic maneuvers correctly and consistently. In return, the plane should allow to learn and refine a wide variety of skills, ranging from very slow flight to basic 3D aerobatics. The plane is not meant to excell in any of those; rather than that it should let the pilot/owner try out and practice all of them before progressing to the more specialized and usually more expensive one.
The archive also has drawings for cutting with a laser or a CNC milling cutter.