The most favorable "trade deals" would be no government imposed trade deals at all. I refer you to the Mike Shedlock link posted toward the beginning of this thread. In it he explains the superiority of free trade over government interference, even if one side has free trade and the other side has harsh tariffs. Even then the country with no tariffs has a huge advantage, and he explains why.
As an aside, could you give an example of a favorable trade deal negotiated by two governments over an unfavorable trade deal negotiated by two governments? What would that look like? What makes it more favorable?