i start my car, let the rpms settle down to a normal idle speed (funny how that happens about 10 seconds or so after i start it) and drive. during the cooler weather/winter, i give it a little more time but nothing excessive.

and like others, i just simply don't rev very high until it is fully warmed up. pretty easy for me since i have about four blocks to get to the interstate which is about the right distance for it to be fully warm (assuming i don't make it though all the lights)

 

Buy a series II and keep the rev's below the moving red line.

In all seriousness, just keep the rev's below 5k unless it's really really cold then wait a little while first.

Also,
If you live in a really cold climate change your engine oil to suit those needs.