I remembered my previous manager telling us, never to say “yes” to a client who wants us to meet/ finish something the next moment. His reason — you won’t be appreciated, and they will just take you for granted.

He was right. Firstly, psychologically, clients appreciate slightly delayed response better because if you take more time, it means it is better thought out. And you are busy. Of course they appreciate you putting in time and effort for it. On contrast, if you give an immediate response, anything wrong it’s because you do it too quickly with little effort. Also, since you can respond so quickly, you must be very free. Furthermore, next time, they expect it to be quicker, or if not as quick, since you are so free. Of course, you need to balance the delay (not immediate, but not …