Last year, during the process of writing up a complex EU reserch project proposal, I was adviced by a Dutch specialist to visualize the list of my sources. She suggested I make this pinboard! The board includes all the main types of historical that I use for my present study, with one specific example from each source category.
Personally, I don’t think it was a very useful piece of advice, but it looks nice! And perhaps there is a point: a table with visual images might make the types of sources that historians use more understandable and accessible to those who are not that familiar with historical research. I hope you find it useful!