One of the things that I learned from Jack Davis at the Sandy Puc’ Workflow tour was a different way to turn images black and white in Lightroom.
The ‘normal’ way is to push the Black & White button in the basic section.
But you can also go into the HSL/Color/B&W section, make sure you are on the Saturation sliders and pull them all to zero.
This gives you a different version of black & white on the image that gives you more options. If you want to keep just a hint of lets say red you can either move the red slider back up a bit or you can use the adjust saturation ‘button’ directly on the picture. (this is the little button in the upper left under Hue.)
Of course every time you want to turn a picture black & white you don’t want to drag these sliders. So do it once, and create a Preset! Go to the left side of the screen and click the + button by presets.
That will open a dialog box and you can select what you want in the preset. The simpler the better. You can have every single adjustment you did in the preset, but if you decide you don’t like part of that adjustment on the image you will then need to manually reverse that bit of the process.
Once you hit the create button turning an image black & white is as easy as hitting your preset!