I have shipped a lot of large items including RC planes and have made crates to fit and have had good luck shipping truck freight and Greyhound.
I too have used 1x2's and 2x2's to make the framework and fiberboard/tileboard for the bottom, and ends. I make a "rack" inside to hold the wing(s) secure. I have access to a box maker machine so I can get a double walled heavy cardboard box for the framework to fit in and a top/lid for it. If not I would just use 1/4" plywood for the "box".
I bubblewrap the wing only where the supports touch it and on each end. I fit the fuse and all other parts inside then drill holes through the bottom board for heavy-duty ty-raps. I wrap the fuse in bubble wrap only where the ty-rap straps will be and on the tail & nose. Bubble wrap the other parts as well. I strap the fuse down via the landing gear usualy wheels off to the bottom, if no gear then around the bubble wrapped fuse with cardboard. Then strap down the other parts. Smaller parts go into boxes and the boxes get ty-rapped down to the bottom.
From my experience do not put anything else like packing peanuts, newspaper, ect.....inside the crate. All that does is add extra weight and doesn't provide any added protection. In fact what it can do if the crate is dropped, kicked, or otherwise abused is transfer the shock to the parts inside cracking plastic canopies, covering, etc.... If everything is secured inside /strapped down , that's all you need. If it's going via a trucking company then strap it down to some pallets.
Also , once it's all finished, mark the outside on each end, both sides and several places on the top and bottom with your return address & phone number and the buyers address and phone number