Putting it simply there are seven types of motes, all of which can be turned into their primal elements for free, just right click on a stack of 10, remember to check on the AH if it's the primals or the motes that are selling for the most, a single primal water may go for 30g, but a small stack (Between one and five) of mote of water may go for more than if you combined it into a Primal. This is a fantastic grinding spot, with the only flaw being it is slowly becoming filled with constant farmers, making it a slow way to get your motes sometimes. However if the plateau is full of other players there are alternatives. For Fire Elements there are several spots, also in Shadowmoon Valley, the most effective being at (34,27) and (47,47) where you will find a large amount of fire elementals and earth elementals. Primal shadow up to primal life are hardly worth the effort., if you ever need any of these grind the more expensive Primals (such as fire or water), sell them and buy the lower ones at cheaper price. The best place by far to grind Motes is the Elemental Plateau (67,23) in Nagrand. This can only be reached by a flying mount, however it does contain a lot of level 70 Fire, Wind and water elementals, all of which drop their respective motes.

My all time favourite grinding spot has to be for Primal Water, this is a spot just south of the Elemental Plateau in Nagrand (58,26) Here you will find hundreds of water elementals (levels 64-66), you can easily get 150g to 300g an hour grinding Primal water here, and that doesn't include the grey drops (about 30g an hour) and the greens 1 seems to drop every 20-30 minutes. This is based on a level 70 with good gear, if you are a lower level it will take you a little bit longer, especially as you will need to take a mana/food break more often! It will however sell for the cost of mats plus upto 30-50 gold, depending on your server. This is a fantastic way to make more cash from your primals, it does however require 350 in alchemy.