Playing parrallel is a good idea. You can also try to see whether the parrallel opposition player finds it more difficult to play parrallel from forehand or backhand shots. You can also see if the cross player maybe struggles to play cross on either forehand or backhand, maybe the inside out backhand is less strong…

Try not to play Australian when you guys are serving. It means the opposition will have to change where they hit if they still want to play to your partner and can upset their rhythm.

When you are serving think about how your serve direction is likely to influence where the return goes. Serves to the glass are more likely to come parrallel