Avoid small swatches on colored backgrounds and single-wall testing, as these obscure undertones and distort color perception. Don’t rely solely on paint store lighting or photos. Instead, test large samples on neutral primer in your room’s natural light throughout the day. Also, consider your flooring, trim, and lightbulb warmth since mixed bulbs can change color perception. Following these steps reduces surprises and helps you select a paint color you’ll truly love.