Hosting massive feasts/banquets is one way, especially when you get into fancy foods, subtleties, etc. Historians in Britain did a documentary reenactment called A Tudor Feast At Christmas.

They show gilding (as in, with real gold leaf) food. I've also heard of (separate from this doc) gingerbread with gold leaf. Look at me, I'm so rich I can waste gold by eating it.

Starting at 11:17, there's one part in there where they make marzipan, and they talk about how extremely expensive the sugar for marzipan was. They give the inflation-adjusted cost of a bag of sugar as £300. They say it was so expensive, that unsupervised servants couldn't go in the room where the sugar was stored. The sheer amount of labor used to powder the sugar and almonds is ridiculous.