We kind of knew it, but becoming a parent also meant becoming a soapbox to our kids. If they are eventually going to ignore us anyway, might as well set the tone on our terms while we can.
When I first started talking to my kids in Cantonese, I was pretty much doing a monologue while holding them. Who knew if they heard any of it, or if they could differentiate the difference between talking and singing, but it was easily achievable while nursing. Usually, the setting was private and nonjudgemental, so it was a comfortable way to ease into practicing the dialect "on my own." But then when not nursing, I'd switch back to English for the day-to-day, and that became counterproductive. I had to force myself to make it a habit to speak to my kids only in Cantonese.
In theory, that's a great goal to achieve. In practice, I speak to them in Cantonese maybe 75% of the time...and that's being generous. When any English speakers are around, I still switch back to English. So I've had to distinguish whether I'm actually speaking English to effectively communicate / be on the same page with my husband, or if I'm just speaking English because it's easy. If it's the latter, I will make a mindful effort to switch back to Cantonese/Mandarin. Obviously, that relies heavily on my ability to check myself. At first, it was hard, but it does eventually become a natural, mechanical, response.
The hardest part was ignoring the instinct to speak what everybody else is speaking around us. Most of the time, people - other parents - totally understand. Very rarely do I have to explain that I'm not trying to be rude by ignoring or translating what they are saying while teaching my kids to speak Chinese. So, when I realized it was just a self-imposed mental roadblock, it was easier to overcome.