I like to narrow down the color by swatch and then use the new small size "testers" that are available for ~$3. A small cost to insure the correct color buy. I like a fan deck of color swatches the best because you can see from one strip to the next what subtle color has been added to change it and choose the correct tint for your color scheme.
After choosing a color or 2 or 3, I put 2 coats of the sample color on a few walls in the room, and then look at it with the furniture and fabrics that will decorate the room.
We recently painted my daughter's bedroom... we knew the "look" we wanted, a calming "spa" blue. We had the bedding chosen and wanted to coordinate the shade of blue to blend with the bedding and the furniture and the other items to be placed in the room.
We tried three colors and were still not totally satisfied so tried two more
I like a muted palette and tend to like a toned down or subtle color. We chose "Rushing River" a Duron color. Duron has recently been bought by Sherwin Williams, but you can still color match to the old fan deck (which I happen to have).I found this useful and fun color tool on the Sherwin Williams website, The Color Visualizer. It lets you choose a room to simulate yours and then you can add the color to the walls and even the trim. Try it! It's a great way to see how the color will change the look in your room. Of course you should still try the "testers" because a computer can't match your room and lighting exactly, but it's a good start.
Remember, there are bazillions of paint colors. They can even custom color match any color you want by machine, so choose all your furniture and fabrics first, look at it all together in the room, and then choose the paint color.
