Hello
It does depend very much on where you want to go, as attitudes to smoking vary quite a bit around the world. California, for example, has very strict rules on where you can and can't smoke, whereas in countries such as Russia and China, smoking is still much more common and people are generally free to smoke in bars and restaurants.
However, wherever you go, you will find somewhere to smoke, even if you have to pop outside the building. Obviously, in warmer countries this won't be so bad.
You might like to have a look at this website, which gives more detail on smoking bans around the world.
http://www.cbc.ca/news/interactives/map-globalsmokingbans/index.html
Kind regards,
Olly, your editor