Bringing water to boil with rice or alone and then add rice?
In his section on cooking rice, Wayne Gisslen makes a couple of frank statements which deserve to be restated here (Essentials of Professional Cooking).

First,


  There seems to be very little agreement among chefs regarding the best
  ways to cook rice.


And second,


  Everyone agrees that the key to properly cooked rice is correct
  proportions of rice to water and correct cooking times. Unfortunately,
  no one agrees on what those proportions and times should be.


So the expert is telling us that, no, there is no rule of thumb. We are wise to acknowledge that there exists so wide a variety of opinions on this subject that neither here nor really anywhere is anyone likely to give/find an assessment capable of bridging those several gulfs, capable of laying down that which is definitive. Each of many answers at variance with one another can still class as a right answer.

I personally never obtain anything other than perfect results by bringing an oversupply of water to a boil, briskly stirring in the rice, pouring off what my eyes deem to be just the right amount of water at just the right stage of cooking, reducing the heat for a few more minutes of cook time, and then removing and covering to allow the residual heat to finish the job. But as my results do not seem in any way superior to anyone else's using alternate or more traditional methods, I do not attempt to claim them anything but more convenient to achieve.