Cache patterns in PHP

No matter how skilled developer you are, sometimes you can't avoid having slow pieces of code - handling remote connections, database queries or just complicated calculations. One of the possible solutions is to implement caching. But the question is - how to do it right? In the following text I'll got through several possible ways how to implement caching in search of the best solution. I'll use the cache storage implementation from Zend Framework 2, but any other relevant implementation can be used instead.