With a few décor tricks here and there, you can make your small house look a lot bigger than it is. Some great aspects to work on include color and shapes.
Bright colors will make the room appear bigger. This is not to say that you cannot incorporate a dark color if you have one of these among your favorites. An easy way to do so is by painting one wall in your chosen dark color, while keeping the rest of the walls brightly painted. Dark wallpaper works just as well if you prefer these to paint.
A second trick that will give the illusion of space in your rooms is capitalizing on the power of reflection. If using paint on your walls, give them a glossy, semi-gloss, satin or acrylic finish. If using wallpaper, choose one that has a glossy texture/finish for that reflective edge.
Materials that are reflective and ones you can experiment with in various rooms include glass and Lucite. A floor-to-ceiling glass window, a glass double door, glass on all or part of the roofing and Lucite or glass furniture will all help keep the room bright and enhance the light in the room.
Pick what works best for each room.