Bubble wrap and strong mailing tape is the way to go. If you have sufficient bubble wrap (normally 2-3 layers wound round the bottle is sufficient) then the contents of the bottle cannot be seen and you are less likely to have it stolen by 'security' staff. After all, who wants to steal a bottle of mango vinaigrette by mistake? The key is that scissors or a knife are required to get inside the poackaging.

I do this all the time and have never had a breakage nor a bottle stolen, unlike friends who use the wrapped-in-a-towel-or-jeans technique.