This is how im doing it...

I have 5 accounts, a, b, c, d, e

a -> b ->c ->d ->e ( -> means Referred)

I have a 71 Druid on A.

I am rushing the FIRST set of toons to 60. (Which means each of the 4 boxes (b through e) can grant 29 Levels to the REFERRER. Thus, Account E will NOT be able to receive gift levels (This will always be the case unless Blizzard allows Gifting To the REFEREE).

Then, I rush the next set to 37ish (Since SM is so easy). Then Grant the second set, levels I earned from Set 1 to the toons on Set 2.
And do that for as many sets as you want.

The downside about rushing, is that Account E will always be lower level than the others from the "second set" and downward, because of the unable to receive gifted levels.

Of course, if you are leveling the Accounts without rushing, this is a moot point, since you will not be using the Gifting, only the triple xp bonus.

Hope that clarified Gifting and Rushing.