YEs a little Expo can help here

You should set it on Aileron and Elevator

Start off with 10% and make 5% adjustments if its too much or not enough that will get you started.

As to wether to use +ve or -ve depends on your Tx JR and Futaba Differ here, on Futaba you use a -ve figure add expo and the opposite on JR (from memory)

Just take one channel, add some expo to it and observe how this effects the servo movement when you operate the corresponding Tx stick.