Should you tip in Hong Kong?

I'm curious, is it customary to leave a tip in Hong Kong when dining out or receiving services? I've heard that tipping practices can vary greatly depending on the region and culture, and I want to make sure I'm respectful and considerate of the local norms. Do service providers typically expect a tip, or is it seen as optional? If tipping is encouraged, what is the general amount that's considered appropriate? And finally, are there any specific situations where a tip would be particularly appreciated or not necessary?