The grip. Better bh or fh in the warm up. Do you win in bh bh? Great. You are better at bh than them, so keep playing it. Otherwise move the ball. Are they bh or fh players, meaning Do they go around from the bh corner? This decide your placement of the ball. Try different serves, are they better or worse at returning some of them? Better at returning with bh or fh? Backspin or Nospin? There Will be allt of pattern in their game so look for that But especially in their serve and returngme. You Will notice that they probly want to return in example with a flip, then they are better at that so try to serve the the opposite meaning backspin. They Will also proably place the return at the sams places when hou Do a certain serve. Aswell look at their footwork patterns, how well they move in different direction.
The basic Idea is that you want to play different shots and be aware of What they chose to Do and how well they Do it. In example if you push long they are proably better at opening with either bh or fh. So you adjust according to that.
Also important with basic stuff like. Ifyou push long you want to have the racket high after to be ready to block. If you loop against backspin you Will have the racket higher to be prepare to loop forward because next balll is block. If you serve Nospin, sidetop be ready for a flip. Push if backspin. So always need to try to prepare a little. Not cheat But just prepare.
But equally, or not more important is to have an own playing style. Know why you re good at, practise this alot and how to get their. So you know how to serve and return to get the balls you want. Without a playingstyle ns Idea behind how you want ro serve, return and play it is more luck if you win. This Is number one, try to play your style of play.. Secondary is to adjust ro the opponent.