I boil the water and pour them into my glass containers. I use the glass because it can stand up to the heat of water, not leeching any chemicals or flavours. I also make these much stronger than I would ever drink them (hot or cold), this way, when I filter out the tea leaves the next day I can store the tea in the fridge and dilute it with ice. This way it makes much more than one container full.
I usually leave it overnight in the fridge, however not all leaves should stay in the water that long, so you just need to experiment. You may want to filter out your leaves after a couple hours.
When I am ready to drink it I just pour it into my glass that is half full of ice and stir in a bit of stevia to sweeten. Generally you need very little, even if you have a sweet tooth! And some teas are naturally sweeter.