The word "stoic" has come down in our language to a modern day meaning quite different from the original. We think of stoic as putting up with things without complaint. We consider stoicism a tough sort of world view devoid of complaint. The interesting thing is the ancient Stoics: Marcus Aurelius, Seneca and Epictetus, thought of the religion as devoted to the pursuit of happiness. A happy citizen is a good citizen. A good citizen is good for society, the stoics reasoned. Therefore they postulated if a society were made up of only stoics then the society would prosper. However, Ancient Stoicism is not an invasive religion. If someone disagreed with the Stoic point of view, the Stoics did not press their view upon others.
The definition of "happiness" in the ancient Roman world was closer to what we modern people would consider basic contentment. During the first through third centuries when this religion flourished Roman politics were in constant upheaval. These were dangerous times for citizens. Seneca himself ended his own life in prison. Perhaps as reactionary to the unsettling times the Stoics considered the goal of life to be "happiness" as apposed to creating wealth, having a successful career in the military, or being a prominent politician. All of these things were ways to create happiness, the Stoics admitted, but they were symbols of happiness and not the goal itself.
In order to be truly happy, the Stoics explained, one must consider and control one's judgment of things. Anything not under your personal control is not worth consideration. Therefore, it makes no sense to be happy or sad because the weather is balmy or stormy because in either case the weather is not under your control. Taken further, it is not worthy to be angry or upset about a personal injustice. If the emperor throws you in jail over a false accusation, it is not under your control. One should maintain a calm equanimity over the situation. One should not even be concerned about one's body, because the body is not under one's control, in that it will age and have normal aches and pains. Seneca even said once, "So what if you are thrown in jail and they cut off your leg? Don't you have another one?"
I would argue that while the body is generally not under your control, it would seem sensible to eat properly and care for the vessel that is taking your around in this life to the best of your ability. The Stoics themselves were not "Hedonists." They, like most ancient philosophers, did not advocate self indulgence. Overstuffing oneself with food as we tend to do, zoning out on television, milking the clock or stealing staplers from work would all be alien concepts to ancient people who presupposed doing things bad for your body or bad for your psyche would be obviously antagonistic to a "happy" life.
One exercise specific to the stoics was a meditation on the terrible outcome. They advocated their adherents would sit and think to themselves once a day on the worst possible things that could happen: for example your home burning down or being thrown in jail. They felt this daily meditation would prepare them for the worst. That way when the worst actually happened, as when Seneca was arrested, he was able to face the situation without (allegedly) stress. One wonders if that were actually true.
Another discipline extolled by the stoics was the ability to make rational decisions. For example, if you are walking down the street and you see a very beautiful woman you may be tempted, for at least a split second involuntarily, to commit adultery. At the very least you may be tempted to flirt with her. However if you are a practicing stoic you can quickly come to a reasonable view of the situation. You might remind yourself that although the woman is attractive now, in 60 years she will be unattractive. If your wife leaves you because of the adultery, this new woman may marry you and pester you or nag. If she is annoying you will have an unhappy life. Therefore you can decide to not pursue her. Similarly if you see a cute little lost kitten on the street and you consider taking the animal home as a pet, you can consider the fact that this cute little thing will grow up very quickly and turn into a cat. This cat will not be as cute and will require a little box and food and other expenses. If you can't go on vacation because you need someone to take care of your cat you will be unhappy. Therefore you should have the wherewithal to leave the cat where it is.
Thus self control and a healthy appreciation for what is not under our control will make for a happy stoic. This philosophy seems to have reinvented itself as a AA slogan: God, grant me the serenity to accept the things I cannot change, the courage to change the things I can, and the wisdom to know the difference. In this world view, you might accept the fact that you cannot get your husband to stop using drugs. You might find the courage to leave that spouse and take care of yourself. You might consider yourself wise for saving your children even if you couldn't save your mate.
There is another saying in AA about not working another person's program. No matter how much we may wish for our loved ones to get sober and clean, many of them aren't ready to. Some prefer to die loaded rather than live clean. Some wander in and out of addictive behaviors, never really accountable for themselves although they may experience bouts without drugs. It really isn't under our control. What we can do, according to the stoics, is consider our loved ones as "on loan" to us. Therefore if your child dies, say "I have given him back." If your house is repossessed say, "I have given it back." And so on, to not spend another minute of this life worrying about things not under your control.