A technique I use is to put ALMOST adequate force on, for example, the bent lever via the 4-5 foot pipe suggested above. Put enough force on the pipe to almost bend it back. Then you need to add additional force EXACTLY where you want the bend to occur. Only takes a LITTLE BIT more force, added to the force you have already applied, to effect the bend in the spot you want it to occur.
This works to bend hooks, loops, hoops, etc. from rods. Use a mandrel in your vise, a bit smaller than your desired radius, put a pipe or strong friend on the open end of the rod, apply force, but follow the rod with your thumb or fingers, applying a bit of additional force right next to the mandrel as it winds around the mandrel.