If you haven't come across the term, schinderling is making a picture monochrome, and then bringing some element of the picture back in colour. 

Relatively easy to achieve in Photoshop if you make a Duplicate Background Layer and use the Eraser tool.

As an effect, I like it.  But like so many other 'special effects', it has it's time and it's place.  Use it more than sporadically, and it's tiresome.

The example above is a great example of the effect. 

It was a dull, damp, dreary day.  I'd exhausted the shine on the cobblestones, so the fire buckets were an obvious next step.  (Yes, the day was that bad!).

The fire buckets cried out to be schindlered, so they have been.

And of course as Derek says, "If you haven't got a least one schindler in your portfolio you're clearly not a hip, funky photographer".

See all my pictures of the Severn Valley Railway.