Conan

Here is how I got the achievement on easy by the time I reached the pier in the Devil Island chapter. The main problem with this achievement is that most throwable items in the environment break after one use, however, there are certain rocks that are "unbreakable" because they are needed to progress to the next area!

In the Tribal Warrior chapter ...
In the area just after the village that is divided in two by a barrier that must be burned, there is a high plateau with a couple of huts and two idols (and two lions at the base of the plateau). When you push the idols over, the rocks fall to an area with a barrier to be broken. At the very least, you can kill the 2 or 3 warriors in the area where the rocks land. You might also be able to lure down the warriors at the top of the plateau, but I'm not sure.
The big payday is in the wind power towers area! You need to push over an idol in the blue wind power tower area to use the rock to break the barrier leading to the red wind tower. This rock won't break until it is thrown at the barrier. I killed perhaps 20 enemies with the single broken idol rock! Warning: as I carried the rock back and forth, I stepped on one of the pads that activates a tower and the idol rock disappeared! I thought I'd have to replay the level, but fortunately there is a boulder that spawns behind the small watch tower in the blue wind tower area. Not only did it break the barrier to the red tower, but it re-spawns if you leave the area. I was able to use the respawns to kill a few more enemies. Note: I also tried to use the burning brazier rock in the blue area, but it shattered against the barrier to the red wind tower and without breaking the barrier.
So to sum up, when you reach the wind power towers area, run ahead to the blue tower area and push over the idol before you kill anyone. Kill everyone you can with the broken idol rock. This will get you well on your way to the achievement.

In the Fallen Kingdom chapter, there are number of respawning jugs of water that you'll use to put out a fire that is keeping you from climbing to the next area. Whenever you cannot see where the jug was, the jug will respawn.

You might also be able to use the rock that opens the door leading underground in the Well of Dreams chapter.

Oh, and do the obvious, such as use the Stone Prison spell to kill multiple enemies with one thrown object.

This one is pretty self-explanatory: kill 100 enemies by throwing things at them. The large vases, crates, and other large objects that you find throughout the game do count towards this achievement, but thrown weapons / shields / torches do not.

If you have the infinite armor power cheat (beat the game on hard) and the stone skin skill, use this to make the achievement easier. Doing this allows you to kill enemies in one throw, as sometimes thrown objects will only stun them (which doesn't count). I didn't do this so it's not required, but it will certainly help.

To be safe, don't try to do this in the same runthrough as Enemy Appetizers - I tried that the first time, and I didn't meet the requirements to get either achievement (there's really only enough thrown objects / impale spots to get one achievement or the other). I suppose it's not *impossible*, but there's nothing more frustrating than getting to the boss and running out of objects / impale spots before popping either achievement.