I tried using a green filter a few times, but I didn't understand how it worked with b/w and didn't like what I got. It was interesting to use the green filter with color IR a few times, but I prefer to use my yellow filter with that stuff.

I used to use red a lot with b/w, but more often than not, I don't bother anymore. I use my IR filters with IR film, but other than the occasional ND grad, I haven't used much in the way of filters lately either.