Here are some tips for getting the most our of your primary sources:
When dealing with a primary source that is a physical object, take the source's physical nature into consideration in your analysis.
Consider the object's provenance and journey. Where did it come from? How did it get to the library or archive it's in today? What factors influenced that journey?
Consider also the object's materiality. What size is it? What is the wear on the object? What can its appearance tell you about its purpose?
When possible, it's a good idea to view your primary sources in person. Scans and other digital renditions of objects are useful, but they don't tell the whole story.
Look for secondary sources – such as journal articles and scholarly books – to flesh out your point of view and inform your consideration of your primary source.
Once you’ve found a likely contender, you can use its bibliography to look for other secondary sources that may be useful in your research – and then do the same with their bibliographies in turn. This process is called "citation-chaining" because you work backwards from works' citations, forming a chain.