Two Gotham party chroniclers got their chance to sparkle Tuesday night at the Paramount Hotel.Lavish book launch for “How to Be Famous in Two Weeks or Less” offered caviar and Krispy Kreme donuts, and co-authors dripping with $4 million in Harry Winston baubles. Melissa de la Cruz and Karen Robinovitz — who both boast clips in a variety of glossies — said they had an edge when it came to fielding interview questions at their own soiree. “I know what they want to hear,” said Robinovitz. Pair knew enough to create a tipsheet listing invited, but unconfirmed guests: Drew Barrymore, Cameron Diaz and Mandy Moore. And even if crowd was mostly strivers and gawkers, at least the writers had an entourage of security keeping them company.