This will probably be considered as common sense by some people, but hopefully it will help someone.
So with the fire festival you can buy Bag of Smorc Ingredients - Thottbot: World of Warcraft Bag of Smorc Ingredients, which will create
Toasted Smorc
Binds when picked up
Use: Increases healing done by magical spells by up to 44 for 1 |4hour:hrs;.
It is quite cheap (only costs blossoms), and VERY useful for raiding, as it stacks with food buffs and flasks.
Both items have a duration of 14 days (realtime). If you simply buy the Toasted Smorc, it will last 14 days as intended.
BUT, if you buy the bag of ingredients (which has a duration of 14 days) and wait until it shows 13 days before opening it, you'll notice the Smorc which are created will have a duration of not 13, but 14 days !
Now that you know this, you can potentially make these last 14days(bag) + 14days(opened), which equals to 28 days of cheap raiding buffs.
Makes me wish I was a healer