There are quite a few locations is Destiny from which you can effectively farm Blue, Green Engrams and Legendaries.
Here is one more such location which has been most productive for farming in Destiny. After you kill your enemy in Destiny he will drop a gem like shiny object which is your ultimate loot in this game.
The location for Engrams farming is Crota, Moon. It will be more effective if you have surpassed level 20. Also it is not totally necessary to do this alone, farm for Engrams and Legendaries with your friends.
By doing this run, you are likely to get more than 10 Blue Engrams, a whooping 50 Green Engrams and minimum 4 Legendaries in just one hour. While doing this run you may come across many Legendary items like Engrams, Exotic gears Legendary Ship Blueprints and a lot of other stuff.
Check out the video given below for the Most Effective Destiny Blue, Green Engrams farming and Legendary run from Crota, Moon: