Sorry for quality of pictures, but it should still get the point across lol
Note: This won't work if another player/enemy is in the spawning area
Start by going to venus and doing patrol
1. When you spawn, choose the path to the right
2. Take that all the way until you get to this point and kill all the enemies in the area
3. Once you kill all the enemies, go straight until to get to this hill
4. Make sure you get behind this rock for the enemies to spawn
5. check your radar for enemies, they will come out of this door in a group
6. Kill all the enemies and go back behind the rock for them to respawn. Continue doing this for as long as you want.
If the enemies to not spawn, then make sure you have killed them all. Some get away and tend to go over here
This is great for beating bounties quickly, such as killing 2 enemies with a single fusion rifle shot, or killing 3 enemies with 1 special ability. Or even doing killing fallen for patrol missions.
not to mention its about 100+ xp per time you do this, which adds up quickly.