Use the color wheel. All the color wheel does is tell you how best to combine colors.There are particular color combinations in the color wheel that are particularly pleasing to the eye, called color harmonies. The basic primary colors of red, yellow, and blue are used to create the secondary colors. Tertiary colors are created by mixing primary and secondary colors together.
There are warm colors and cool colors. Warm colors tend to be orange, red, yellow, etc. and cool colors are greens, blues, and purples. Mixing warm colors with warm colors and cool colors with cool colors can be a good way for a color coordination novice to get comfortable with the colors.
White, black, and grey are neutral colors (and are very important for properly coordinating clothing).
When a color is tinted that means that it's getting lighter (has white added to it) and when it is a shade it is getting darker (has black added to it). Tones in a color are created by adding grey. When you're coordinating clothes you'll need to see how different tints, tones, and shades work with one another
Avoid complementary colors as much as possible. These are the colors that emphasize one another and are opposites on the color wheel (say for example, orange and blue). Don't let the name fool you, these colors are complementary to one another and that doesn't mean that they'll be complementary to you!
Now, you don't have to avoid pairing complementary colors completely, especially if you're a bold and confident dresser. A good way to use complementary colors to good effect is to pair 1 complementary color with a paler tint of its opposite color. For example, pairing a royal blue dress with a pale gold shawl and shoes
Use analogous colors. These are the colors that are right next to one another on the color wheel, like green and yellow or red and orange. Because they are close to one another they appear easy on the eyes when paired together.
An example of using analogous colors to good effect might be a scarlet red dress with gold jewelry and pink shoes.
Try to avoid putting no more than 3 analogous colors in one outfit. To use the above example you've already got 3 analogous colors (pink, red, gold), so you wouldn't want to go overboard and add in orange too or purple.
Use primary colors. Primary colors (if you can think back to your basic schooling years) are red, blue, and yellow. These are hard to pair together unless you're really brave, although they can look great when done right. Primary colors are great, though, for the monochrome look, which means that you use only one color.
An example for the monochrome look might be a white top paired with dark blue skinny jeans, dark blue ankle boots, and a dark blue jacket. To alleviate all that blue you might add in red or bright purple scarf.
An example of a good use of primary colors together would be to use it in conjunction with multiple neutral colors. So you might pair red chunky heels with blue skinny jeans and yellow jewelry, while breaking up the colors with a black jacket and grey top.