A guy came in for a phone charger and I walked him up to the better cable and the case, and he bought both. I am good at it now, the pitch lands. But part of me still wonders if I just talked him into money he did not need to spend, and that part does not quite shut up.
More people experience this than they realize.
You can upsell, but doing it without feeling manipulative still bothers you.
If this sounds familiar, the Library can help you find the bigger picture.