Build the one wing panel, then raise it up 3/4" at the last rib, then build the other panel flat on the plans. Make sure the left panel that is raised is flat on the board at the root rib. This sets 3/8" of an inch overall wing diheral and also sets the dihedral angle in the center. This is easier than setting the wing dihedral angle after both halves are built. When you build the right panel, make sure you sand angles on the spars so they mate the left wing panel. You will probably glue the root ribs together and add dehedral brace(s) when both panels are built. Hope this makes sense and helps