Stoicism is a philosophical mindset based on logic. It's something that has been used by kings, presidents, the greatest philosophers, and me! It's a highly regarded mindset which I've basically summed up below.
The Dichotomy of control
It's basically understanding what you can and can not control and reacting accordingly.
Let me simplify this with an example; if it's raining today and you have to travel far, you can either complain about the rain and have no impact as the weather isn't in your control or you can suffice the disturbances of things outside your control ( weather) with your actions like
bringing an umbrella.
Choosing what side you take an action towards co-relates with your happiness; if you complain about the rain you'll have negative feelings of unhappiness but if you take the umbrella you'll be able to choose to be tranquil.
The story you tell yourself
Stoics say that the negative emotions we feel aren't because of an external event but because of how we've perceived that or in other words what story we've told ourselves.
So the idea is to understand the way you think of something is totally in your control, basically giving you control over your happiness.
Expose yourself to pain
As humans, we tend to overthink and have insecurities, which makes us suffer more in imagination than in reality. The way stoics thought of this was to result to exposure therapy. When you do something you were afraid of or thought would cause you pain, you'll more often than not realize it's not that bad and your fear was unnecessary.
In the simplest example, if you're scared of dogs, spend some time with dogs and you'll realize that they're harmless.
Prepare for the worst
The idea is to mentally prepare for a possibly bad scenario so that when it comes you'll already be mentally prepared and won't flinch. The second benefit is of feeling more gratitude when you realize your worst-case and aren't actively living in it.
This is applied to doctors and soldiers; you don't want soldiers to learn how to shoot a gun when the enemy attacks, you want them to prepared for that scenario.
These are the principles or exercises I connected with the most, there are multiple areas you can dive into and explore but this'll get you to understand the basics!
Personally, I don't regularly relate real life situations to Stoic principles and sayings but the basic idea of accepting what's in and not in your control has stuck with me and has become a part of the regular way of thinking!
Hope you found this helpful.