This is a question about looks in a written document. I has nothing to do with LaTeX, although I create my documents with that. Is this the right site then?
I write lab reports and other documents where I have to include a lot of images and tables. Those are usually floating within the text and are referenced to via numbers. As you can see in the image below, I use a serif font (Bitstream Charter) for the main text, a sans-serif font (Bitstream Vera Sans) for the headings.
To distinguish the caption below the image, I have changed the font to sans-serif. That gives it a distinguished look, but it also feels a little too distinguished. If you look really close, you can see that the “mm” are set in serif font, since that is math and that uses serif by default.
Is there some other way to distinguish the captions visually from the remainder without using a different font variant or shape?