To learn how to detect micro-expressions there is no easy way to become proficient. The more that you study the faster and more efficient you will be. Here are some micro-expressions to use as references for your learning process.
These images are of a man from a T.V. show called Lie to Me. The show is about a Dr., featured above, that is a facial expression expert. He makes his living off of determining whether people are lying or not based off of their facial expressions. Above lists some micro-expressions and what happens to different parts of the face to form these quick but honest expressions.
Here is another example of these micro-expressions
Here is another example of these micro-expressions
There are certain expressions that are said to be "universal" and these are those expressions.