Get personal. A proper thank-you should never be typed, even if your handwriting borders on illegible. “Always use your own stationery” instead of relying on the standard, store-bought cards.
Show some emotion. It’s more than acceptable to “go a little overboard and ramble on a bit in a stream of consciousness.” You want to “find the mot juste” for the gift or experience that was offered.
Actions speak louder than words. Sometimes a note is “simply not enough” to express your gratitude. A bottle of wine or small bouquet are subtle ways to show added appreciation.