I think the vary the revs thing is a load of bull myself although it can't hurt.
I don't think the rings can tell the difference between 3000 and 6000 RPM. It's still the same section of ring going over the same section of cylinder over and over again. as for the 1 hour or 3 hour or 24 hour driving once the lubricants are up to temp. The temp will remain constant. I have owned and operated heavy comercial trucks for a period of 8 years and rational thinking wins out over wives tales, superstitions,and hocus pocus every time.
When a vehicle is new bedding the brakes and seasoning the tires is the most important thing as well as a proper starting procedure.
The way I like to season tires is to bring them up to normal running temperature and then allowing them to cool down to ambient temperature 3 times before any sustained high speed driving is performed (120 MPH or over).
Normal everyday driving in north america should accomplish this. There is a good article in an old car and driver magazine where they ran a Ferrari Maranello on fresh tires at high speed and had severe problems with them.
Bedding the pads is very similar to seasoning the tires. You want to get the brakes up to temp without making any very hard stops. once this is done allow them to cool. Do this 3 times and your brakes will be bedded.
I believe the most important thing is to start a modern fuel injected car properly.With your foot off the gas turn the key to the second position. Wait a few seconds for the fuel pump to reach its' pressure. With your foot still off the gas turn the key and start the car. Modern electronics do not require you to goose the pedal for the car to start. This will prevent you from putting extra load on the engine when the engine is cold and the internals are unlubricated. Allow the engine to warm up a little before driving off. Even then don't go too hard for the first few minutes till the transmission, differential and brakes come up to temperature. Once this is accomplished DRIVE IT LIKE YOU STOLE IT!!!!
P.S. always use a torque wrench to tighten your lug nuts to the proper specifications in the proper sequence to prevent disc warpage.
If someone is using an impact gun to install your tires make sure they use a torque limiting socket on their gun.
NOTE: Common sense is always required. You shouldn't warm up your car in an enclosed garage nor should you be gentle on the brakes should a child jump out in front of the car.