iTunes' Genius mixes are a good idea in theory, but sometimes they don't give you exactly what you want. If Genius keeps giving you duplicates of certain songs (or adds songs that shouldn't be there), here's how to improve them.
Perhaps it's because I have a small library, or perhaps it's because I only listen to a few select genres of music, but I was never a fan of Genius playlists in iTunes. I often hear the same songs over and over again, and sometimes one or two artists that maybe shouldn't fit in the playlist get added anyway. After finding this little trick on Mac OS X Hints, though, I've found that it makes Genius mixes a little bit better for those rare times that I just want to shuffle some of my music.
The trick is this: Let Genius create your mixes for you, but instead of listening to them from the Genius menu, head into iTunes DJ and tell it to use one of your Genius mixes as the source (make sure to head into its Settings and show a large amount of songs, too, like 100). Next, create a new playlist and drag a song from the iTunes DJ section onto it. Once you've done so, head back to iTunes DJ and select all the tracks and add them to the playlist. iTunes will warn you that you're adding duplicates to the playlist. Hit the "Skip" button to ignore all those dupes.
Now, you'll have a Genius-like mix with a good number of songs on it without any duplicates. If you want, you can even refresh iTunes DJ and add songs again (once again, skipping duplicates) to get a larger playlist. What's also nice about this is you can add (or remove) anything Genius didn't catch but should have, so you have a more tailored, dupe-free, Shuffle-friendly mix. Hit the link to read more.
Eliminate Suprises and Re [Mac OS X Hints]