I've been strangely drawn to doing portraits in monotype lately. It's not a process I was familiar with before this past semester, but it was the preferred method of my printmaking class's TA.
If etching and lithography are like drawing, monotype is like painting. It doesn't have the reproducibility of other printmaking methods - you only get one. You take flat, thin, non-absorbent surface (either an etching plate or plexiglas) and work onto is with ink using more or less whatever you want. Alternatively, you can create a subtractive image by inking the whole plate and then wiping away with a rag or brush or what-not. I started out having a lot of fun with the latter, but I've been leaning more towards additive or a combination of both.
I'm digging the re-work-ability of monotypes too. Once they're dry, they can totally be gone back into with another medium. Colored pencils have been doing it for me; the juxtaposition of painterly wiping with precise line work feels kind of satisfying.
And I don't know why, but I keep doing these Victorian Death Portraits! I find the darn things immensely fascinating to look at it, and a lot of times I'm banging out some monotypes while I'm waiting for a plate to etch or a print to dry enough to add the next color, so I guess it's a natural gravitation.
