This can be a difficult one to plan.
It is probably easier on the lower level opponents. If you ever see an enemy on 1 hp, or near enough so that you can reduce their hp to 1, make sure that you do not defeat them.
Set the opponent up as much as possible to reduce your health.
I did this on the rats in the Ruined Keep, but didn't plan it :-(. They blocked an attack that would have killed them, and then killed me in the next attack.Please either comment below or send me a Personal Message if you have any comments or improvements.