Hey Slicepong, patience andbnit rushing in games is something a lot of players find hard to get the balance with and like you say ot is a thin line between being aggressive and rushing. Definitely being relaxed in s a big part of it and keeping the shots a smooth action.
On the high ones that’s very common to rush them, you always haveva bit more time than you think on them, so try to focus on hitting through the ball solid at the top of the bounce rather than attacking too hard.
If you go for a decent speed shot into a good area often you can win the point without going to fast and adding to the risk. Even if your opponent does get it back,you should then be in a good position to play again. So I’d say try to take the pace down and think about taking another shot to win the point, even if you feel you could kill it straight away.
I also really like the feeling on smashes of thinking about it in 2 parts which can slow you down, so the first part is the backswing and preparation and the second is rotating through, weight transfer and arm swing. With a little pause between the 2 parts, just a split second really. Some players I’ve coached found this idea really helpful.