Sending flowers before or after the party is also appropriate. The Dutch avoid superlatives. A person who never offers criticism is seen as either being simple-minded or failing to tell the truth. A foreigner need not worry too much about saying something the will hurt feelings. The Dutch will argue, but seldom take offense.
Dutch humor is subtle rather than slapstick.
The Dutch speak directly and use a lot of eye contact. To a foreigner, them may appear abrupt, but it is just their manner of communicating. Holland is a region within the Netherlands. Smoking is prohibited in many areas. Always ask before lighting up.