Toph said..I don't see how plain packaging Works. I would hazard a guess most people taking up smoking these days take it up due peer pressure. A doctor certainly not going to prescribe it due to a hard labour. In other words, somebody is going to be introduced to smoking by somebody that already has a packet. After that, it doesn't matter how well they are hidden away, how many closed doors You put them behind, or what you put on the packet, if you are going to buy cigs, you are going to by them.
Increase the legal age to purchase them, and price them out of existence.
disclaimer, I acknowledge that pricing doesn't always work either. I was going to give up smoking when the price reached 4 bucks a pack. I think when I finally did give them up, they were about $20 a pack

I have never been a smoker, but I would argue that it has removed brand awareness.
In my local hardware store they also sell a few groceries, and cigarettes. When they changed to plain packaging, I asked them if they had stopped selling cigarettes. No they hadn't, but unless you really looked you wouldn't notice them.
When I was a kid, people would smoke because the cool kids did. When this number drops, by whatever means, less people will smoke.
I am sure there were unethical shop keepers selling cigarettes individually to kids when I was at school. I guess this sort of thing would not stop, but if its a couple of dollars each it may.