I used to warm up my old I30 before going, but realized after reading many posts on the internet that a warm-up procedure is NOT required and not always recommended.

In my G, I simply turn it on and wait about 20-30 seconds and get going, driving easy until I reach optimum engine temperature.

I once had a 2005 G sedan loaner with only 10k miles on it...one cool morning (around 35 degrees F), I was late for work so I turned on the car and floored it out of the lot. I looked in the rearview and noticed a huge cloud of bluish smoke that you see from those old Lincoln towncars/Ford Crown Vics and a bunch of the late 80s dodge caravans. Dunno if there was another problem, or if the smoke was due to me not warming it up.

As far as cooling down, there is no such thing. When the car is idling at normal temperature, it builds the most heat up inside teh engine bay, and thus the engine itself, when the car is sitting idle. You are in fact warming the car up even more than cooling it down. You may consider pulling into yoru parking space, immediately turning off teh engine, and then raising the hood for a while if you wish to cool-down, otherwise just shut off the car and it will cool on its own. This is what coolant is for.