After performing a Battogiri (attacking with sheathed sword) technique, wait until the attack animation has completely finished - then tap R1 + R2 simultaneously. The sword is re-sheathed instantly (rather than waiting for the long animation usually triggered when sheathing the sword) ready for another Battogiri attack! (This sometimes works after normal attacks, kens, tai etc.). If you get good at doing it you can fight with the sword permanently sheathed, and string tones of Battogiris together - interspersed with sheathed sword counters etc.