I recently posted on this (going 3 to 5), but your situation is somewhat similar.

Two basic decisions you have to make:

1. Are you going to be boosting your accounts with a 70 (or higher).

2. Who do you want to get the zhevra mounts.

Assuming your current accounts are A and B.



If you are NOT going to be boosting, then you should RAF as follows:

A->C

B->D

Whoever RAFs E (it can be A, B, C or D), will get a zhevra mount (or a second zhevra mount if it's A or B).

In this case, your plan would be to roll 5 new toons on the accounts and level them together (whether questing or instances). Everyone in the group benefits from triple XP. You can use the gift levels to level up your current toons on A and B. Thus, you might want the NEW toons on A and B to be a different class than your current ones.

If you have a 70+ on account A and you DO want to Boost with that account.

A- NO RAF to anyone

B->C, B->D, B->E (3 zhevra mounts for B)

Here, no matter what you do, account A will not benefit from RAF. Thus, no triple XP, no gift levels. However, you can use all the gift levels that B will get to level a toon to 60 and transfer him to A (25 bucks).

As far as when to use the gift levels: As far as gifting levels is concerned, it does not care if it's level 1-2 or 59-60. You can't gift past 60. So, ideally, if you have 20 levels to gift, use them from 40 to 60. Also, if you are 1% from leveling and you get gifted to the next level, you will STILL be 1% from leveling to the next level! This means, you can gift yourself to 59.99 if your XP bar is nearly full.