Why don’t you go for a Guiness World Record? (The answer is that I applied for the World Record as Richest Player in World of Warcraft in November 2015 but they “do not invite proactive applications for records such as the one you are proposing” and suggested I go for “world’s longest Warcraft livestream” instead. Zzzzz no skill needed, no thank you!)
For example, the Azure Whelpling belongs to the Dragonkin family. However, it has Beast, Magic, and Elemental abilities in addition to a Dragonkin attack. Different attacks are strong and weak against different family types. Having a diverse spell selection might increase your chances of being prepared with a strong attack against an opposing team.
This farm almost did not make this list. Even though I have had only a little luck with it, it seems to be gathering some popularity in the gold farming community. Although I feel with the recent changes in 7.3, this farm is very close to dying out. Generally what you want to to do is pull every mob you can as you venture to the last boss in the instance. The only saving grace of this farm (if you can call it that) is that some mobs are GUARANTEED to drop greens. Guaranteed. Whether or not they drop profitable greens is a different question, however it's a must-mention quirk you get from running this instance. It also allows you to get your hands on some rare low level blues.