Basically...

A > B > C
A > D > E

You ideally want to boost in sets of four.
And then do your level granting.

But you can do them after each set, if you like.

Once you have a toon that is 80th (or anything lower, really).
You would create a toon on the recipient account.
Meaning C is granting levels to B, so B needs a character to receive them.
You have to be on the same server as B was, when the RAF took place (so cannot grant C to B, on a new server... even if you did character transfers).

B creates a toon, and levels them to 2nd... and as close to 3rd as possible.
If you ding 3rd, then get very close to 4th...
You need to be 2nd and not 1st, for maximum effect.
C targets B and can run a macro, or right click on them and select grant level.

Your giving/granting toon has to be higher level than the recipient.
So with an 80th, you can grant a level to a 79th, making them also 80th.

When you level the toons with RAF, they can give one level for every even level they gain, up to 78th.
So that is 39 levels to give, if you level 1st to 80th (78th).
If you make a DK and level from 55th, you're not going to get 39 levels, only ((78-55 = 23) /2 = 11) 11 or something very close to that.

Code:
Put this in a macro, on the character granting levels:
/run GrantLevel("target", 1)
 
And the second for the veteran account to accept the levels:-
/run AcceptLevelGrant()