I use dashes and semicolons heavily, and I always distinguish between the two - dashes feel like a leap to the next clause; semicolons, by contrast, a more measured, thoughtful transition.

I often end sentences in three dots as a kind of "you fill in the implications" thing, particularly for deadpan jokes. Apparently this is kind of a Gen X thing that younger people find a bit passive-agressive...

...and I do THAT as well. I also resort to Capitalising Every Word Kanaya-Style When Employing Heavy Irony.