Hope this belongs in the guide section...if not please move to exploit...
We all know that the lootsystem for LFR was changed with the release of MoP. We are no longer rolling on a fixed quantity of items. The system preforms the roll for every raidmember and maybe you get an item or not.
The loot that you receive is being selected for your role. For example Restoshaman get mail gear with Int + Spirit.
BUT...what most people don't know, the system does not take the role that you are officially performing in the LFR. You receive the loot for the spec that you are using in that kill.
What to do:
1. Queue as Tank/DD or Heal/DD or Heal/Tank
2. Get invited to LFR
3. Check which role you are being assigned
4. If this role is what you want to receive loot for, everything is fine
5. If you are invited as...let's say DD but you need loot for your Heal-Spec, then just change to your healing spec and do the encounter in this spec. You will still be officially assigned the role of a DD.
6. If you receive loot it will be for your heal spec.
LFR is quite easy. But I would not advice queueing as tank and then switching to DD, as some of the encounters require 2 Tanks...even in LFR. But you won't notice if there are 3 tanks or just 5 healers running around.
Unfortunately I cannot provide a pic as I forgot to take one. But in my last LFR I was invited as DD. As one of our tanks struggled mightily I decided to spec Tank just to have a backup if he dies once again. In this run I received the tank trinket with mastery and dodge-proc.
Have fun guys.