1. Start with a reference point
If you aren't sure which color direction to go in a room look to the colors you are drawn to in the items you already own. This could be a piece of art, an area rug, throw pillows or other accessories. Pull your favorite color from these items and start to consider the options within that color family. If you are redecorating an entire space, leave the paint selection until other major elements are selected. There are an infinite number of paint colors to select from, while items such as area rugs or upholstered furniture pieces might be more limited. Save yourself some trouble and wait until the end of your selections to select the paint.
2. Consider how you want the room to feel
Color plays a big role in how a space feels. For example, do you want your room to feel light and airy? Go light. Or do you want the room to feel intimate and warm? If you are going for the later, consider a deep, saturated hue.
3. Get samples
This is the fun part, but have some restraint. Just because you can take home all of the samples doesn't mean that you should. The more you take with you the greater the chance you will feel overwhelmed when you get back home. Start by pulling lots of options but see if you can narrow things down before leaving the store. If you can, bring your reference point (or a photo) to the store so you can easily eliminate options that are clearly not going to work.
3. Hang samples on the wall to narrow down your choices
Once you have a few front-runners, tape the samples to the wall. It's important to hang the samples on the wall because that's how you will actually experience the color - not looking from above if they are spread out on a table. Remember, adjacent colors can change your perception of a hue. Isolate the particular swatch in consideration and hang something neutral, such as a blank piece of paper, behind the swatch if necessary.
4. Consider finish
Finish is both a practical and aesthetic consideration. From a practical standpoint, a matte finish is not as durable as an eggshell finish but it is easier to touch up. A finish with a higher sheen wipes clean easily but it will emphasize imperfections on the wall. With that said, paint technology continues to improve and the matte finishes are getting more durable. Showrooms such as Hirshfields are a great resource on the latest paint types. From an aesthetic standpoint using multiple finishes can create interest and variety in the design.
5. Test the color(s) and leave up for at least one day
Do a test sample on all four walls in the room you are going to paint. I recommend doing all four walls as the color can actually look different depending on its orientation in the room. Look at the samples throughout the day to see what the color looks like with different light sources (natural vs artificial) and at different times of day. Certain color undertones may be highlighted or be less noticeable depending on these factors. You'll want to make sure the color appeals to you at all times.
A last piece of advice is to not over analyze. There are so many colors available it's easy to drive yourself crazy. Remember, you can always repaint! Do you plan to repaint any rooms in your home? What are the biggest challenges you face when committing to something new for your home?
PS - If paint selection or other home decisions are stressing you out I share my tips to prevent design and remodeling decision burnout in a past article which can be found here.