Greeting
Informal greetings are: hoi, hai, hé, môgge (short for goedemorgen)
Neutral and formal greetings are: goedemorgen, goedemiddag, goedenavond, goedendag, dag.
Saying goodbye
Informal are doeg, doei, daag, doeidoei, later. Regionaal zeggen mensen ook: (de) mazzel, houdoe, aju/ajuus.
Neutral and informal are: dag, goedendag, goedemorgen, goedemiddag, goedenavond, tot ziens, tot straks, tot zo, tot volgende keer, et cetera.
Note
You will likely find goedenacht as a translation for good night. While technically correct, goedenacht is hardly used. When it is, the intention is close to sleep well – although welterusten is a much more common way of saying that. If you simply greet someone in the evening (in coming or going), you would use goedenavond.