A simple trick I finally learned from Lightroom is how in black-and-white photography, we should feel free from the rules. Until recently, when making a black-and-white print, I started from a colour picture that was more or less optimised. Not completely finished for printing in colour, but with colours corrected, the right white balance, etc. With some (pedantic) disdain, I never used Lightroom's presets to convert that picture into black-and-white, but did so by and, fiddling carefully with the greyscale controls that work more or less like the channel mixer in Photoshop: you can control how light or dark eight parts of the spectrum (from red to yellow, to purple and magenta) will be represented. And then I'd adjust the overall contrast to get nice dark, yet sufficiently detailed shadows and good highlights. That was before LR2; since then I'd add some dashing and burning in parts of the picture.
Once I tried the LR presets though and found that they used different effects: no use of the grayscale mix at all, but simple desaturation and ruthless adjustment of exposure and white balance! I won't follow their route completely; I'll keep using the grayscale mix to have better control of how my blues (sky!), reds (skin!) and greens (plants!) are converted into tones of grey, but radically changing the white balance (usually to a low temperature setting, say 4000 K) was an eye-opener that helps to get strong effects that work well in black-and-white. For it is the effect that counts, and we are not accountable for the numbers of the colour temperature to be correct!
The photos are symbolic of 'working'--seemed fitting to today's theme. They were was taken in Hanoi, earlier this month.