I only have one emotion I regulate, which is anger. If I'm alone, I take a quick breath as soon as I become angry and tell myself, "It's not worth it. If I keep being upset, it will resonate in my body for hours and fuck up a large portion of my day." That seems to do the trick.
With other people, it's a lot harder. Me and my ex used to argue all the time. She was very rude and had no patience for anything, so it was a blowout every weekend until I finally ended it. During this time, before I realized she was so toxic, I would practice de-escalating, like roleplaying in my apartment alone how I would feel and how I should react when the next fight came. This worked to an extent, but I'm a disagreeable by nature, so once I hit a certain point, I don't care to be nice anymore. The only thing that worked for me in those scenarios was just to leave and come back when I cooled down.
The only other "emotion" I regulate is the light level depression, which I think of more as a state than a feeling. And for that, I always just take some action, the smallest thing I care to do at the time, that I consider to be meaningful. Like, I'll say, "I'm just going to do laundry and shave and clean the house a little," and even if I just do one or two, then I consider it a win. More often though, that leads to an avalanche effect where I wind up getting a lot done and feeling great. Sometimes not, but it always makes me feel better that I just did something rather than nothing.
