Do this exactly, and you'll have the best chance of survival. I think this is akin to what sully did.
They declared a bird strike with all thrust lost and returning only seconds after it happened. Within 5 seconds they had a return heading. Again, maybe I am taking this too literally, but here is my thought on a takeoff engine loss:
Step 1: (WWII pilot recommendation) LOWER THE NOSE! and fly the airplane.
Step 2: (While returning to the airport) Tower xxx emergency need trucks
From there, let them figure it out. They can clear the way bring out the trucks and maximize my chances for survival should my landing not be perfect. I will get medical help as quickly as possible.
A simple key up to say anything can help though, here is an example:
I was in the run-up area when a guy on a student solo (near license thankfully) had an engine loss on short final at 200 or so feet. First thing he did was key up and say, "I am going in the field."
As soon as he got off the radio I keyed up, "Do not stall (or watch airspeed, can't remember) - Will (FBO desk operator) call 911 we have an aircraft with an engine failure landing in the field short of 28."
He came back asking what, for which I repeated. We had helicopter traffic on sight (the CFI had first response experience) in under 30 seconds. I was down the runway, in my truck and there maybe a minute later. Needless to say, if he needed any help he got it in under a minute after landing. This was an uncontrolled field without emergency response teams.
It took about 5-10 minutes to have police, ambulance, and others there.
Edit: Aircraft totaled/pilot fine. Crashed into light brush, between trees at or just above stall speed.