Based on the title, I think you're looking for an abort procedure.
Like eagle said, first make the decision to abort prior to overtorquing or drooping Nr below limits.
After you make the decision, it really depends what your choices are. If there is only one spot below that is safe to hover IGE, then you'll have to descend to it. If you've made the decision early enough, maintaining current power and allowing a slow descent works fine. You don't want a rapid descent to start because the small power margin you've given yourself may not be enough to stop the descent. Remember that you will get an IGE power advantage eventually.
If there are other places to land/hover IGE then consider them before you take off. You should always have an abort plan, especially for a MP takeoff.
If there is a spot in front of you worth using, then I would descend vertically until I reach a point where a dive for airspeed and subsequent flare could be accomplished to that spot. This is a procedure you'd want to practice in an open area first, to gain the judgement.
Is this what you're looking for?
Matthew.