Start by considering the color palette of your countertops. Look at the dominant colors and undertones. You can either choose a backsplash tile that matches the color of the countertops for a seamless look or opt for complementary or contrasting colors to create visual interest.

If your countertops have a busy or bold pattern, consider balancing it with a simpler backsplash tile. On the other hand, if your countertops are more plain or subtle, you can add interest with a textured or patterned backsplash. It's important to strike a balance between the patterns and textures of both elements to avoid overwhelming the space.

Coordinate the materials of your countertops and backsplash tile to create harmony in the design. For example, if you have marble countertops, consider a marble subway tile backsplash for a cohesive and elegant look. If you have a more contemporary style, you can mix materials such as glass or metal for a modern and sleek aesthetic.

Pay attention to the undertones of both the countertops and the backsplash tile. If your countertops have warm undertones, consider complementing them with a backsplash tile that has similar warm undertones. Alternatively, you can create an appealing contrast by pairing warm countertops with cool-toned backsplash tiles, or vice versa.

It's highly recommended to take samples of your countertop material and various backsplash tiles home to see how they look together in your space. Natural and artificial lighting in your kitchen or bathroom can significantly affect how colors and textures appear. By viewing the samples in your own environment, you can make a more accurate assessment of how well they complement each other.

If you're unsure about which backsplash tile will best complement your countertops, don't hesitate to seek professional advice. Interior designers or tile specialists can provide valuable insights and help you find the perfect combination that suits your style and preferences.