Start by choosing an accurate color wheel!
The color wheel you (probably) grew up with is a lie, it does not produce real color harmonies. It's "compliments" are visually unpleasant and garish.
The Musell color wheel/system on the other hand produces true color harmonies:
Big color concepts in a nutshell:
Examples of color Harmonies. Most color harmonies are based on choosing colors that are equidistant from each other on the color wheel. However in my experience there is no simple formula for really getting color to work well and the following harmony systems are just a starting point.
This "emotional color wheel" is not perfect, but it's an adequate starting point for exploring the emotional tone inherent in some colors. Take it's advice with a grain of salt.....