For my work-in-progress I knew I wanted a Mediterranean-like secondary world setting with an archipelago and a pre-medieval lifestyle. My research on the Phoenicians triggered ideas for clothing, trade, habits, food, etc. A search for pictures, especially of Phoenician clothing and sea-faring vessels, revealed the type of details I was looking for, too.
Also very helpful was @rebekah.loper’s book #The A-Zs of Worldbuilding. That generated even more avenues for plot and setting.