i usually plan where i want to hit the ball and then react the serve.
i also usually expect people to serve to my backhand on first serves, so i plan on returning with that grip and then react accordingly (changing grips if the serve is to my forehand).
If the server has a weak one, then i'll hit an inside out forehand or backhand, depending on which side of the court. I'll hit cross court and hard.
If the server has a good one, i'll return as I do the 1st serve.
Disclaimer: I'm NOT a coach...
Real tennis: https://www.youtube.com/watch?v=yDqnkLJ9BtM