Best way to do it is to overcompensate before hand, I have the same problem as you with my recurves alot of the time. What you do is, make sure you leave a good amount of extra width so that you can just remove the excess to get a good alignment friendly recurve after bending incase they twist or go to the side.
EDIT: Also, for your problem at hand, I suggest googling heat bending or heat correction, and I am sure you will find some good info. I personally can't help much in that department.