Use 'never mind' to make someone feel better about a mistake or oversight. You dropped a plate? Never mind, it was an old one anyway.
Pro Tip 2/3
Redirection
'Never mind' can steer a conversation away from a minor issue and onto something else. The reservations are lost? Never mind, let's just go somewhere else.
Pro Tip 3/3
Casual Dismissal
Use this phrase in casual settings, not formal ones, to dismiss concerns. We're out of sugar. Never mind, we'll drink our coffee black.