The first post still works, but now that the two-way harmony integration is out of beta, most people, including me, are using that smartapp instead of the IFTTT step.
So everything is the same except instead of setting up IFTTT recipes, you set up “harmony triggers” using the following FAQ:
That way everything just runs a little faster. But the whole virtual switch concept is still the same. 
But there are a lot of different ways to do it. It really just depends on how your household uses your home entertainment center. At my place we have a lot of different people, some using echo, some using the button remote, sometimes during the same viewing session. So synchronization is a big issue for us.
If you live by yourself and you’re only using echo, you don’t have to be as fussy about the switches.