Making the most of space: Manuel Fernandez: Minimize private rooms; celebrate the public areas. It's the same idea as on a boat: Give the spaces you use for sleeping and bathing only the square footage needed to make them work, and give the rest of the square footage to the public space. I think, in general, bedrooms are too large.
Maximize the light: MF: Use many, many shades of white. Here, the starting point was a premixed color called Super White from Benjamin Moore. If you want to add color, make your florist your friend. Or add color with the artwork. Instead of a painting, have a supersize photograph, and print it on Plexiglas so it becomes another reflective surface.
Jane Krolik: If you can't have a skylight, try either a light running up a wall, or carve a little well into the wall and put bulbs in there. Faking it is the best way to do it. Lee's Studio has a very good selection of lighting, from soup to nuts.
Experiment with materials: MF: Plastics and polycarbonates are great for partitions and ceilings. Polygal is a flexible one we've used a lot -- it comes in different finishes and even in color. Ain Plastics (249 East Sanford Blvd., Mount Vernon; 914-668-6800) is a good source.
JK: Sometimes I go to the fabric district and walk down 39th or 40th Streets -- a lot of fabrics eventually end up in those stores, like vinyls and so forth. I also go to Long Island Fabrics in TriBeCa (406 Broadway, near Canal Street; 212-925-4488).
Fixtures and fittings: MF: Hit your local hardware stores. Any Ace Hardware, literally -- they have the largest selection of common artifacts. Also auto-parts stores: At body shops, you can buy mirrors, upholstery, even cleaning supplies like Armor All. The small light fixtures on automobiles are very good to use in small residential spaces. And try the Sweets catalogue -- available online at www.sweets.com.
Rugs: JK: If you're going to have a carpet, keep it small if you want things to be cozy. If you want wall-to-wall carpet, try to keep it the same color as the wall. You can have heavier, traditional pieces if you love them, but use them as an accent, and let the rest of the room be clean. Carpet Innovations (588 Broadway, near Prince St., suite 803; 212-966-9445) has got some of the best things -- I like Paola Lenti.