I'd like to pretend I'm an authority on this kind of stuff but I just have another opinion, just like most.

Here are some technical differences between a modern bike and your 'new' Royal Enfield.


Modern bikes have a coating on the inside of the cylinder wall on top of the iron (essentially) sleeve...or in some cases...straight aluminum alloy...really, I'm not making this up.  This coating is called Nikasil.  Extraordinarily hard and very thin on the surface of the cylinder.  It's made of Nickel and silicon.    

Your bike does not have this fancy material.  It's pure old school.  Old school recommendations for break-in apply.  Anyone, please check my reco here.

1.  Vary your RPM regularly.  Don't drive long distance at the same RPM the whole time, very it by a few grand, up and down the range.
2.  Be nice to it.  Some say, ride it the way your will ride it.  Uhmmm, nah, be nice.  Take it up the rev range once it has a couple hundred miles on it, redline once in awhile but initially, there is more friction going on here.  The hone cross hatches against the rings will create a little more heat, so be aware of that.
3.  Heat - be aware.  Think.  Sitting in traffic, rush hour traffic, not good to overheat your little teacup.  Avoid it initially or turn off the motor if your in that traffic jam.
4.  Oil - Change it a lot.  I read a Popular Mechanics article where the guy was changing his oil every 20 miles!  I'm not that fanatical but I did have a bike where I did it every hundred, guess what....looked like very fine flaky metal within the old.  As all the bearings, camshaft against lifter, gear on gear wear themselves together and create good mating surfaces the thing is going to have an accelerated wear rate.
5.  Your brake pads and discs need to mate together too.  No high speed stopping or dragging on the brakes immediately.

I'm not saying don't have fun, I'm just saying.  Be aware, don't beat the hell out of it, vary the engine speed and change the oil a few times for the first 1000 miles.

Others opinions will differ.  Hope this helps, good luck and stay upright.....and please be a helmet guy, if not for you, for the people that care about you.