This kind of thing would normally be done discreetly, but apparently Mitt Romney hasn't consulted Newt Gingrich privately on the matter. So instead, Gingrich offers his debate "advice" to Romney in a column for Human Events:
Relax and be prepared: "More important than what Romney knows is how he feels."
Be assertive and be on offense against both Obama and his media: "The strongest reactions I got to my debates came from people who were desperate for someone to stand up to the media and redefine the questions and reframe the assumptions."
Be honest: "People can smell dishonesty and disingenuous efforts to sell or hide."
Use humor: "No president in my lifetime has been as vulnerable to humor as President Obama."
Enjoy the evening: "He should relax and bring to bear a lifetime of experience at decency, honesty, determination, applied intelligence and hard work. He will do just fine."