So the way to get double loot from LFR. First of you do LFR like normal, get your loot etc. *Not needed*
This method requires you to have a full 25 man group in order to do this *NEEDS TO BE SAME REALM*. First off you get a raid composition together and queue into any LFR queue (not sure if it needs to be 90 equivalent), but just choose an MOP LFR queue. Once everyone is inside you all teleport out "Do not drop group". Once you're all out you run to the raid "Heart of Fear" Located in Dreaded wastes. (coords 35,35). You all zone into that raid and you can start killing that instance.
The thing with this is that you will be killing this raids bosses, which is ilvl 489 gear. It won't be the same bosses that you queued for in LFR. You will be fighting bosses that will be released in the future (2 weeks) that are inside Heart of Fear. Although, the bosses will be LFR difficulty, it won't be 25 man normal difficulty, so it will be easier and you will get loot just how you would for LFR. You can do this an infinite amounts of times. In other words, once you finish that raid you can re-queue and do it all over again.
This is only effective for two more weeks since this raid will be released then. I have not PERSONALLY done this, but I have very reputable sources that have knowledge of guilds doing this. This was working as of yesterday.
*NOTE* This is an exploit which means BANNABLE offense.. There have been many EU guilds that have already exploited this, no word on if they were banned or not. So please, do this at your own risk, and good luck on gear!