Hi Spockey,
I speak English (no code switch) to my girl and my hubby speaks Cantonese (again no code switch) to her. But I speak Cantonese completely to my hubby all the time as he is more comfortable and refuses to speak English.
My in laws speak Cantonese completely and little Mandarin to her, and they care for her in the daytime.
I hope I am doing this right because I really want my girl to get a good start in English and I am trying to keep up with speaking English to her at all times since she was 8mths old and now she is almost 1. English is my native language btw, and though I speak Cantonese, is it not highly fluent.