In India, there are talks of banning vaping altogether. At the time of writing, such a law has not yet been enacted, but is being prepared. We recommend you to check the latest news before departure. At the moment, there are some restrictions in five states: Jammu and Kashmir, Maharashtra, Punjab, Karnataka, and Kerala. Production, sale and import are banned there.
They also say that in Goa vaping is kind of forbidden, but Jesus, it's Goa we're talking about! According to eyewitnesses, the customs don't care about vapers, and the same goes for the state's territory.
The European Union has a TPD (Tobacco Products Directive), which prohibits the sale of devices with a tank capacity bigger than 2 ml (RDAs are also illegal) and of more than 10 ml of nicotine liquids — but this doesn't apply to storage and import for personal use.
Local restrictions on imports exist in Finland: you can't carry more than 420 mg of nicotine in solution. That is, you can bring 140 ml of .3%, or 420 ml of .1%.
And you are allowed to bring up to 150 ml of any liquid to Switzerland. For personal use only, sale is prohibited.
Naturally, we're only talking about completely legal border crossing. We did not consider the option of illegally importing vape liquids in perfume and liquid soap bottles. You shouldn't consider them either.
Also, we advise you to follow basic ethics principles. Don't vape if you are in a crowd of people (for example, at a bus stop), in close proximity to children or in a room where not everyone is fond of thick fog. Avoid conflicts, they never lead to anything good.
In general, people everywhere are more or less fine with vaping, so you don't have to worry. Of course, stuff can still happen: a lot depends on the rules of an airline, the mood of a customs officer, sometimes even on their personal attitude towards you. So try not to bicker with anyone, don't bring any suspicious-looking bottles, don't vape into the airport employees' faces, and your vacation will go smoothly.