Ice cube tray breastmilk storage question ...

LM :)
Hey Ladies,
I've read that using ice cube trays works very well for storing smaller amounts of breastmilk ... But before I try this, I have 2 questions:
Can I use normal ice cube trays with a lid and sterilise them before use or does it have to be special breastmilk storage trays? 
Also, once i take the cubes out of the tray can i freeze them in normal ziploc bags (and label them with date) or do I need to use breastmilk freezer bags for example the Lansinoh or medela ones? 
Thanks! 
Thanks!