Color Combination Confusion

The skill of combining colors and layering kinda confuses me. I heard someone say that the ability to succesfully combine clothes is one of the most essential parts of a good style. I would like to know more about it, since I’m a student and therefore money is limited, so I need to be able to combine the more cheap clothes into something stylish.

Tie and Shirt Color Combos

I am curious though, How can you determine what color/pattern tie to wear with a colored shirt? Are there any laws of fashion that state anything? i.e. shades of blue striped tie on blue shirt, or is that going too far?