2 layers of vacuum seal with deodorant under the nuts always works for me, i prefer to keep it on-person.
Appearance counts as well, sometimes i would dress like a bit of a dork or a nerd or someone that looks straight-as-nails and they wouldnt look at me twice.
i was with friends of mine last year coming back from Queen's day in Holland, i checked through before em sober as a judge, they ducked out to smoke a joint (idiots), came back in stoned and goofing around, one of em started messing with a dog, which was a drug sniffer, it barked, and they got busted with 50g.
so yeah be fresh headed and confident at all times and good luck