From Shinjuku Station to Omotesando Station:
Take the Marunouchi Line to Akasakamitsuke Station, change trains to the Ginza Line to Omotesando Station (15 minutes, ¥170)
From Tokyo Station to Omotesando Station:
Take the Marunouchi Line to Otemachi Station, change trains to the Hanzomon Line to Omotesando Station (16 minutes, ¥200)