One of the most challenging "grind" techniques that we do as part of a workout has got to be the Turkish Get-up or the TGU. The TGU is a perfect (or torturous) blend of strength, flexibiliy and mobility. At first glance it doesn't look that difficult - but once you are under that kettlebell and try to get moving it's a totally different experience!
As always there are a lot of really TERRIBLE examples of the TGU o youTube and elsewhere. You need to understand that there is a good reason behind the way we (the RKC community) does the TGU. It has to do with supporting a HEAVY load (not a light one where you can muscle your way through improper and unsafe technique) and transitioning while maintaining it above you on the way up and down.
Watch the following video for a good example of how to do the TGU (By CrossFit Koncepts Dynamic Duo: Dos and Liz)