Spend more cognitive resources on dealing with positive feedback.

When someone says that you have a nice shirt, think about why they said it. Probably they wanted to make you feel good. What does that mean? They care about making you feel good. You matter to them.

Gratitude journaling is a tool with a good evidence base. At the end of every day, write down all good feedback that you got. It doesn't matter if it was trival. Just write stuff down.

Meditation is also a great tool.

Curiously sociopaths have the opposite issue, underresponding to negative feedback.

I wouldn't be sure about that claim. I think sociopaths rather have different criteria of what constitutes negative feedback. I think physical pain would have the same effect on a sociopaths as on a regular person.