It's easier to make than you think and it's the first thing to do when it comes to decorating a room. What you'll need: preferably big white paper, a triangle, a t-square, enough tracing paper and perhaps the most important tool, an architectural ruler. After you take two measurements of the room making sure to include doors, radiators, stair landing window seals and their respective heights, also take notes of electric and telephone outlets. It's always a good idea as long as you take measurements to draw an unofficial floor plan as well as take pictures of the place to remember it accurately. Once ready to start drawing decide on the scale you want to use. I prefer to use a scale of 1/4 or 1/2 because I like the furniture to look big enough. After having the floor plan of an empty room then the fun part begins. Having enough tracing paper will allow you to be able to try different furniture layouts without having to erase anything. A T-square will keep your drawing straight. Don't be afraid of your not-so-good looking drawings, the shape of the furniture don't need to be as perfect as long as the measurements are correct. Have fun and go and make your room as beautiful as you deserve it.
Above a (rough picture) of a floor plan of a living room/dining room of a home I'm currently working on. The wallpaper under the floor plan is Spring Close by Brunschwig & Fils hopefully my client will agree on putting it on her foyer.