This achievement is extremely easy. When you set a trap and then set a second trap the first one automatically gets picked up and put in your inventory. While this is unfortunate for setting up ambushes, it is very useful for getting this achievement. All you have to do is have two traps in your inventory, place one, then place the other, and repeat this until the achievement unlocks. You will have to go into your inventory and set the traps to the quick item menu after picking them up, but that's really all there is to it.
Also, you can do this if you only have one trap, just place it and disarm it then repeat until the achievement pops.