I used the airfoil shape from the mini speedster, but I cut it as a simple rectangle. In fact, it's as long as a DTFB sheet, and 7 inches wide. Since I didn't want to fuss with polyhedral, I knew I needed to make ailerons, so I cut them and glued on a couple 5g servos to control them.
My fat fingers were incompatible with the deep narrow fuselage of the ft mini speedster, so I wanted to make it wider and shallower. BUT, I wanted to use the same mini power pod, so I wound up making the fuse 5cm wide (inside), and putting in 2 spacers on each side of the power pod. Nice that the DTFB seems to be exactly 5mm thick.
The tail went together quick and easy, just cutting it to what looked right.
I put an angled former into the fuse just to stabilize and strengthen it, and found that (including the spacers for the PP) it was already quite stiff, so I didn't feel the need to add a bottom, or a top near the tail.
After having been so frustrated with the CG I messed up on my mini speedster, I decided to make the wing adjustable. I put panels on either side of the fuse, but only glued to the wing. A saddle. Then I was able to lightly tape it in place, and move it around until I found a CG I liked. Once again, I referenced the mini speedster; I used its CG point, just in front of the wing fold. Once I was happy with the CG, I didn't go back and glue the wing; I just added more tape. Packing tape is SO STRONG (not that I have to tell you).
My fat fingers have such a problem with clevises and linkage stoppers. I'm so happy to use the FT technique of simply bending wire to the right length, and gluing the (centered) servo in as a last step.
I bought the crappy colored packing tape from Amazon a while ago; I wasn't happy. This time I read these forums, and bought from northland wholesale, and the colored tape I got was very good. My decoration isn't beautiful, but was designed to help me with perspective in the air.