It's not any issue! In addition to visiting museum websites (which is especially good for jewelry), there are blogs focused on historical fashion I check 😭

If you're looking at a place to start it can be helpful to pull up the Wikipedia article for the culture you're designing for and then look at the listed references to see where they pulled images or information from, then head to the links provided ^.^

It's also helpful to look at historical art from the region, especially for ancient cultures where it's unlikely that any fiber art survived the passage of time 😩