I don't, I've been to Amsterdam once, bought a gram (was a daytrip). I would go and buy my weed in Amsterdam more often if I had a car (and a driving license for that matter). It's a four hour trainride (wich is quite expensive, more expensive than gas atleast) and trains are regularly patrolled by cops near the border, so importing the goods by train is not an option. Hopefully by next year I'll have my license, importing it by car is no problem. Finding weed (illegaly) in Belgium is extremely easy, most dealers buy their shit in Amsterdam anyway, so I smoke Amsterweed without having to do the trip