Are you referring to the sets for the Fokker D.VII?
I haven't done the Roden kit.
I just completed doing the wings on the Eduard kit. With the exception of the wing's trailing edge, I start by trimming the decals to exact size. When applying the decals I start from the center (top wing) and work towards the edge. I was using the transparent decals and had pre-shaded the wings using an off white color before starting. When using the transparent decals it's imperative to align the rib tapes with the ribs on the wing. This resulted in a very slight gap (about 0.5mm) between one rib on each side of the wing (port & starboard) on both the top and bottom of each wing. This was later touched up using a liner brush and some paint matching the rib tape color which was blue. If you were using the white background lozenge (non-transparent) and had painted the wings a darker color beforehand this wouldn't be an issue and it would not show.
The other items that needs some attention is the wing tips and the ailerons. I cut several small lines in the outer edge (1.5mm) to help the decal to conform to the compound curve of the wing tip. On the ailerons, the middle hinge doesn't hatch the cutout so this area requires some touch up as well.
Note: I use Gunze's Mark Setter (underneath) and Mark Softener (overtop) solutions with good results. Don't let the Mark Softener puddle on top the decal. I use a soft brush to wick off the excess.
Hope this helps and good luck!
