One of my most loved Amarok features are dynamic playlists. For those who don´t know how they work a little guide is availible.
I use a tweaked random for my dynamic playlist. Amarok is told to play music from a smart playlist which contains all the songs I rated with more than 3 stars or did not rate at all. I don´t want to listen to music I have listened to within the last month. So I exclude that as well. This makes my smart playlist. In Amarok it looks like this: