Jessica Simpson is a generous tipper.

The singer, actress and reality TV star recently left an extra 60 per cent on a $500 restaurant bill after dining with her mother, assistant and two other friends at New York Italian restaurant Lavo.

As well as leaving a $300 tip for the $500 bill, she also left a positive message to her waitress, telling her "you were amazing and make this world a better place, Love Jess."

Jessica had told her waitress she'd had a hard day at work and ordered Macallan 18-year-old single-malt Scotch whisky, which she drank with ice and paired with an unusual dish of fried Oreo cookies as well as a veal parmigiano.

Jessica, 30, has been in great spirits since announcing her engagement to Eric Johnson in November, and recently admitted she was left speechless and in tears when Eric popped the question.

Talking about the proposal, she explained: "I had to sit on his knee to really get what was happening. I was shocked.

"I first said, 'Yes!' But I didn't even try The Ring on until 5 minutes in. I just sat there and cried with him."

Jessica was previously married to singer Nick Lachey from 2002 until 2006.