Nationalistic composers expressed their nationalism by?

On the one hand, by using ethnic harmonic, good examples would be Béla Bartók's work and Chopin's mazurkas and polonaises or the polish lullaby in his scherzo Op. 20, as well.

Other composers stated their patriotism in the titles of their symphonic poems, as Jean Sibelius (Finlandia) or Smetana (Má vlast, could be translated as "My homeland").

Or they composed about traditional Fairy Tales like Edvard Grieg (Peer Gynt).