Get rid of the maple motor mounts, go with 1/64 ply doublers, use a composite of 1/16 balsa and 2 pieces 1/64 ply for the LE bulkhead. Mold your balsa rather than carve it, watch how much glue, especially epoxy you use. Cover the wings and stab with Monokote or Ultracote. Taper your control surfaces, go with 3/32 control horns if it is a 40 size stunter, etc. Cut off the extra lengths of wire for the electrics, use a lightweight CF prop and spinner. Use those thin very light weight wheels, Don't have excess lengths to your metal hardware, no pilot, no instrument panel, use contest wood, build up your flaps, stab, and elevators. Go ahead and build up the vertical fin too! Wrap your lead outs to the minimum of AMA specs, and keep them as short as possible, use the lightest weight line clips too. Hollow out wing tips, enlarge holes in bulkheads and wing ribs without weakening them, use the heavier balsa on the outboard side, minimum size fillets, minimum number of hinges to be safe, CF push rods with ball links, CF bell crank, and last of all use a light weight tip weight box!