By his last decades Nabokov lived in a hotel, and his writing day moved through a small study one posture at a time. He started upright and ended flat on his back, following his own body's complaints.

The Direct Answer
Standing at a lectern in the morning, then an armchair, then lying down.
His Montreux routine, described in Strong Opinions and his 1964 Playboy interview.

A Lectern in the Morning, a Couch by Afternoon

For nearly two decades Nabokov and Véra lived at the Montreux Palace Hotel on Lake Geneva, and he did most of his writing in a modest study there. He began the day on his feet at an old-fashioned lectern, an upright stand that let him write standing up. As the hours wore on and his legs tired, he shifted to an armchair beside an ordinary desk. Later still, when his back began to protest, he lay down on a couch and kept going. He described the whole progression himself, with the dry humor that runs through most of his interviews.

I generally start the day at a lovely old-fashioned lectern I have in my study. Later on, when I feel gravity nibbling at my calves, I settle down in a comfortable armchair at an ordinary writing desk; and finally, when gravity begins climbing up my spine, I lie down on a couch in a corner of my small study.

Vladimir Nabokov, Strong Opinions, from his 1964 Playboy interview

The lectern wasn't an affectation. Standing kept him alert in the forenoon, when he did his sharpest work, and the move to chair and couch simply followed his stamina. He wrote everything by hand on index cards in pencil, so the furniture only had to support a small card and a writing hand, which is part of why he could migrate around the room so easily.

The hotel setting matters to the picture. Véra was a few steps away throughout the day, typing the cards he finished, handling the correspondence, and reading each draft before anyone else did. The workspace was small, but almost everything he needed was inside it or just down the hall, and the arrangement suited a writer who wanted his days quiet and his meals handled.

The Car, the Walks, and the Rooms Before Montreux

Nabokov didn't only write indoors. In his American years he drafted on cards in the back of the car while Véra drove him on butterfly-collecting expeditions across the West, and parts of Lolita came together that way, between one meadow and the next. He also composed a great deal in his head on long country walks, shaping sentences before a card ever caught them. Decades earlier, as a younger man, he had written in bed, dipping a pen into an inkwell on the night table.

Before Switzerland there were rented rooms and borrowed desks. He taught at Cornell and wrote in houses he sublet from other faculty, moving often, never owning a home. The lectern-and-couch study at Montreux was the closest he came to a fixed workshop, and it arrived late, once his books had finally made it possible to live off his writing.

The particulars of the room were plain by design. He didn't want a shrine, just a place to stand, a place to sit, and a place to lie down, all within a few steps of each other. Everything about the arrangement served the writing rather than the image of a writer at work, and visitors who expected a great man's grand studio tended to be surprised by how ordinary the corner really was. The lake and the hills gave him his walking ground, and the cards waiting back in the study caught whatever the walk turned up.

See the full Vladimir Nabokov writing routine.

What You Can Steal