In my practice, is seems that equanimity of mind has been a result of practice rather than a discipline of it. Over time things did not bother me as much. Dealing with difficult circumstances because easier with a clearer head as there was space to think carefully about the situation, choices, and results. Because I was less confused, there was time to reflect on myself and my life. My confidence rose as I accomplished more. Knowing myself better reduced fear: fear of losing, fear of winning, fear of the unknown, fear of myself. I was not filled with anxiety or worry, and as a result more energy was devotedto the things that were most important to me - family, friends, studies, myself, the world.
And this isn’t to say that I never feel the negative emotions, but I see it like this:
Your stress, is like a glass of water. If your stress is low, there is very little water in the bottom and therefore a lot of air circulating freshly above it. Then one day you have an important job interview, and someone pours a little bit of water in your glass so there is more stressd. After the meeting you go home and the level eventually evaporates. Maybe you can even speed the evaporation process by doing relaxing activities like watching House and taking a long hot bath.
The problem for most of us is that we get the job we applied for, and then we start pouring water into our glass. Perhaps we throw a few other things in the glass also: lemons, a stack of paperwork we need to bring home, a few shots of whiskey… and the level just keeps rising. We treat our minds like I treat my purse - to me it is endless. Now some of us have tiny glasses and we fill up and overflow right away, freaking out on everyone and quitting our jobs. Some of us started with a large glass, and the climbing water level really doesn’t hit us until we’re nearing the top and realize something is wrong. At that point, we try all the things that used to work: taking that long hot bath, going for a walk, watching a good movie… and maybe it helps a little, but it just brings that level down a bit.
So - emotions? Feeling? Was that what we were talking about? I think that the air at the top of the glass is for emotion. If someone makes you angry, the anger dances around on the surface of the water like a little fire, fogging up the sides and steaming up the place until the wind catches it and floats it out the window. The more space there is, the better the cross breeze. The less space available, the more likely you are to get burned or start sizzling up the water. In the same light, if you love someone, the love has a lot of room to float around (imagine the aurora borealis in your Kleen Kanteen)… If the water glass is full, you don’t have a lot of room to love. You’re always worried that there won’t be enough room for everyone, or that someone is going to skip out of the glass and go somewhere else maybe. This is sad. 
So - what I am saying is that with consistent yoga practice, I have learned all of these incredible methods to keep that water level stable and still at the bottom of the glass. The emotions - love, joy, sadness, pain, fear - they haven’t disappeared, and I don’t experience them less - with a mind they are free float around me with banging into things. I see the emotions and the impact they have which much clarity because there is nothing blocking my vision. I don’t love less, rather I can stand back and love more without being suffocatED or suffocatING. There is less thinking and more caring. I hold someones hand genuinely, I embrace longer, I look into the eyes of everyone I speak to and I listen intently. When I was younger, fear dominated all my relationships in one way or another, and now that feeling is gone.
Anyway. That’s just my story. haha.
Time for bed!