Quick alert, remember that when patch 6.0 goes live, Justice Points and Valor Points are going away.
If you have Justice Points on you right now, please make sure you spend them quickly for the best benefit. If you WANT Justice Points and the things they can buy, it’s very easy to farm them fast by running normal Pandarian instances. Each boss kill gives you quite a lot (more if you have the guild bonus) and normal instances can pop fast. If you have solid LFR or Flex (or better) raid gear on your character, they fly by.
A few tips on spending Justice wisely;
Heirloom Items are currently bought with Justice Points. DO NOT spend them on Heirlooms right now, when patch 6.0 goes live you’ll be able to buy all Heirlooms and upgraded Heirlooms with gold. GOLD. So don’t spend Justice on these.
You can upgrade blue quality weapons with Justice, but honestly, why would you want to? If you need a weapon upgrade that bad, consider going to the Timeless isle and farming Timeless Coins to buy one of the epic weapons there, they are a better deal.
You can purchase Honor Points with your Justice Points. This can be a great deal for you, IF you don’t like to PvP.
More on Justice to Honor.
500 Justice Points will buy you 250 Honor Points at a vendor in your faction capital city.
You can buy PvP mounts with 2000 Honor Points each, so for every 4000 Justice Points you can buy a nice PvP mount. Looking for a few more mounts? Don’t pass these up!
There are many cool looking PvP armor sets that you can buy with minimal Honor Points. The old sets are discounted heavily. You can find a really nice list by looking at Transmog sets on Wowhead.
On some of those PvP sets, especially the Outlands ones, you can exchange normal PvE tier tokens for the PvP armor version. That means, for many Outlands PvP armor sets, you can run the old raids solo, get tier drops, trade those in for PvP versions of the armor, and only need Honor Points to buy Boots, Belt, etc. Doing this saves you quite a lot of Honor Points on building a set.
I just wanted to give you this heads up. Don’t forget to use ‘em before you lose ‘em.