On those kits where the wing is glued permanently inside the fuselage, you can usually do as pinball said - cover first, assemble second.

After the wing and fuselage are covered, slide the wing in place and line it up well. Then use a permanent fine point marker (Sharpie) to mark the fuselage side on the wing.

Cut about 1/16 inside that line to guarantee that no bare wood will show. Slide the wing back in and glue it in place.