Stoicisim is described as a life philosophy. In my mind, it amounts to a collection of time-tested values, methods, and advice that usually makes your life better.
Like anything of non-negligible value, these techniques often take a few months to a few years to develop.
Imagine deeply what your life would be like without something you currently posess - if you had lost it. Then, when you go back to reality, you're more likely to appreciate what you have and qualm your insatiable desires for more - desires which often unsettle and destroy people.
Dichotomy of control
Understand what you can control and you can't. This saves you a lot of wasted time and effort.
Stoics believed in fatalism - literally, fate predetermined our past, future, and present.
You can be fatalistic about your past and present, so that you don't get too worked up about circumstances that you cannot change. This is equivalent to being deterministic.
Being fatalistic about your present, as we now know, is misguided.
Ocasionally deny yourself pleasures like good food or a comfortable existence so that you immunize yourself against a future where you could loose them for real. This reduces anxiety about any loss you could incur (since you could deal with it easier) and helps you combat the hedonic treadmill.