If you regularly use your iPhone for voice notes or recordings and also like playing your music on shuffle, you'll have had the jarring experience of music being interrupted with unwanted memos. Eliminate that problem by using a smart playlist.
While the failure to automatically exclude voice notes from shuffle does seem like something of a design flaw on Apple's part, it's easy to build a smart playlist to get around it. Start a new smart playlist (Control-Shift-N), and define a rule where Media Kind is defined as not Voice Memo. Ensure Live Update is enabled, and you'll have a playlist ready for shuffling that contains all your music, but none of your memos.
If building smart playlists is unfamiliar territory, check out our Lifehacker 101 guide to what else you can do with them. Thanks to Chris O for the idea!