Fiery Keeper of the Hat
@Benjamin - I think that is the best approach.
Let's be clear: The best approach is whatever is right for the author and the writing. Some people find research to be more helpful than others. I personally find research to be more inspiring than anything.
I get the impression that people assume the point of research is to include more long boring text blocks of irrelevant detail. I get the impression that people think that research blocks out creativity and limits your ability to imagine new settings. That shouldn't be the case. Research can help to inspire new ideas or reinvent old ones.
I was looking through a wikipedia article about technology in ancient Rome, and I saw that they had invented the Cameo. I had no idea what a Cameo was, so I clicked on it. It's an image carved into a certain kind of gemstone right where it changes color, so that the image is in one color (usually white) and the background another color. Take that into a fantasy world, and imagine a wizard's talisman as an engraved gemstone - take it further, two separate gemstones, engraved and fused together - and you have a compelling image for Master McGuffin's Powerful Artefact of Doom. The random piece of information enhances the writing and the story and the scene rather than merely clearing up a few facts about how long their tunics are.