Choosing good color clashes involves understanding color theory and how colors interact. Consider complementary colors (colors opposite each other on the color wheel) for vibrant contrasts, analogous colors (colors next to each other) for a more harmonious look, or split complementary colors for a balanced contrast. It's also important to consider the context and the emotional impact of the colors. For a visually appealing result, experiment with color combinations and pay attention to the color's intensity, value, and saturation.