Alan Cumming, now in “Cabaret” — again — started as an entertainment writer. “In Scotland, at 17, I went to drama school and worked for a TV magazine. Best thing I did was to completely make up the horoscopes. I’d read magazines, see what they say, then make up my whole thing. Like I’d write: ‘You’re going to do great things . . . coming into a wonderful romance . . . your world’s about to expand.’ ”

And his mindset now that he’s a high-class actor?

“I take care physically. Some form of exercise. Yoga, pilates at the gym. Get the body moving before we start. I arrive two hours before curtain. Take a little nap. Then the dress and makeup gets me going, and I get into character.

“Everything goes on in my dressing room. I have a Crock-Pot of soup that I make for everyone on my little electric stove, and they come in before the matinee. I’m like a nanny.

“I’m also their alcoholic uncle. My dressing room has a stocked bar. It’s drinks afterward. I serve vodka, Scotch, whiskey, Campari.

“I live here now, but I have dual citizenship. My mother’s still back there, but she’s coming over. I’m getting her an apartment. My awards are here in the East Village. They’re going to Boston University, which has my art collection and all my show business s - -t.”

DeNiro Sr.’s NYC pad untouched

Bob DeNiro’s late father’s private, guarded downtown art studio is untouched from the ’70s. Blinds closed, skylight shut so no sun. In winter, controlled heat; summer, air conditioning. Cleaned constantly; no dust. The son’s face mirrors his famous father who, he says: “labored with the intensity of a monk in isolation” and is in the Whitney, Smithsonian and Met.

There are boxes of artwork, canvasses in slats, walled sketches of flowers, expressionist paintings, books on Matisse, Rodin, Klee, Modigliani. Drawings of the family. Bob himself never posed. “I couldn’t sit still long enough.” As you may have heard, Perri Peltz’s produced/co-directed “Remembering the Artist: Robert De Niro Sr.” shows it all on HBO June 9. This personal documentary is father/son devotion — one talent fazing out, another coming up. Junior narrates.

Gracie’s gal

First Lady Chirlane picked Meredith Horsford as executive director of the Gracie Mansion Conservancy. Previously serving as manager of historic sites, Horsford’s background is keeping our city’s fabled landmarks open and accessible. Gracie, one of our oldest wood structures, is a member of the Historic House Trust.

Watch. For Bill’s first cocktail party, they’ll probably serve mead.

Pay attention

Bumping Justin Bieber on the Time 100 poll (making fifth place), Laverne Cox celebrated at the Broad Green Room, which Broad Green Pictures opened for Tribeca Film Festival . . . Marlo Thomas, selling her new book “It Ain’t Over . . . Till It’s Over,” hosts today’s online National Day of Reinvention . . . Ken Chenault, CEO of American Express, didn’t leave home without it. Paid his Le Cirque dinner with his AmEx card.

Mob shmob, we’ve had it

Enough already with mob wives. These screeching bummettes scramble with one another, get indicted, and now comes the book “Mafia Girl” by Deborah Blumenthal. A fictionalized whatever about a don’s daughter and the Family her family’s into and their kill ’em, shoot ’em, break your legs violence.

Nice. By Thursday, she’ll probably get an offer she can’t refuse from Bravo.

A 23rd Street sign reads: “No idling.” It posts a fine. I can’t report the amount of the fine because in front, blocking it, parked an empty bus that’s idled there since Henry Ford created his first horseless carriage.

Only in New York, kids, only in New York.