I have several friends raising children to be bilingual. They predominantly speak the mother's language at home, one is French and the other German and have the rest of use speak in English to the children.
I think it's just continual exposure that does it.
My kids are multilingual. For a start, though he was born in Dominica, my husband's family is primarily Israeli. Half are very strict and use Yiddish daily, some use Hebrew all the time, not just for synagogue. My DD1 learnt Welsh first (I spent an age teaching DH the language so he'd be able to vaguely understand the kids) then Hebrew and finally English. I am from North Wales and my first language was Welsh. Strangely enough, especially as some might think it a dying language, we speak mainly Welsh. I feel most comfortable in it, and my kids use it very well. They use Yiddish or Hebrew when they're being very serious about something, and English when they're moaning about stuff. It's funny actually- our dog has learnt 'come', 'stay', 'heel' and 'walk!' in three languages: Welsh, English, Hebrew. I have a multilingual dog!
Hi I'm a nanny and I teach French to the little ones I care for. My number one rule is to speak only in French to the little ones and respond only in French as well. I also do lots of activities involving the language for example- singing, using flash cards, playing games, baking and reading. The little ones really enjoy when we bake the letters of the alphabet and sing along after.
If anyone else has any tips or activities I would really appreciate it.