The best-designed hotel rooms often come down to the details. Blackout shades, well-placed light switches and other thoughtful features can make all the difference. “If someone has anticipated these things, that’s the biggest gesture of hospitality you can offer,” said Jo Littlefair, who with her husband, Martin Goddard, runs Goddard Littlefair, a London- and Portugal-based interior design firm that’s worked on projects like the Mandarin Oriental in Vienna and the Gleneagles Hotel in Scotland.