Clean your home before taking a journey/trip.
It just sucks to come home after a long day in the car/train/plane and your desired home is a mess.
Tidy up at least a bit, wash dirty dishes, do the bed (!!), and you will feel welcome when you return home.
Stopping at red light.
It maybe close to unthinkable for people in the US or Europe to run a red light. But in my home country Vietnam where there are a lot of motorbikes this happens ALL THE TIME.
Grabbing all empty drinks, trash, jackets out of the car every single time you pull in the driveway so that it stays clean.
Asking questions. I swear 99% of complications in interpersonal difficulties in life are from people being too afraid to step on toes, hurt feelings, or just not taking the time to understand people that all comes from a lack of asking questions and an abundance of assumptions.
Leaving for the bus/train etc a bit earlier so that you don't have to stress in the last second or risk that the bus/train leaves too early
Double checking that a ballistic missile attack is really happening before sending out an alert to a whole state.
Ensuring your keys are where you thought you put them. Because you may think they're in your purse. But they may actually be hung up around the bottom of a bar stool in a restaurant that's about to close. Just saying...
Removing valuables from your car.
This might be more specific to me, but I work a sales job and I track all of my revenue. I make revenue in two separate areas, with spreadsheets for each.
My coworkers don't do this. They just rely on management to track all of the revenue that actualizes. While complaining, at the same time, that they don't get paid enough, that they are being shorted on their commission.... But how do they know they're being shorted if they don't even track it?
I go through every sale that I make, as I make them. and then every day, I check to make sure the sale actualized. Then at the end of the month I calculate my total commission, and check it against the incentive check my boss gives me.
This way, if its discrepant, I can point it out. And I can also plan my finances accordingly, so there's no surprises when my commission isn't as great one month.
I have made more money since doing this. Like several hundreds of dollars more every month, because then I can put a strategy into place if there are areas where I see I need to improve. It takes me maybe 10 minutes every day. But my coworkers say they don't have the time, they just want to complain that their check isn't as much as they thought it would be.
Calling an older relative just to say hi and see how they’re doing - it only takes a few minutes, but it means the world to them to hear from you.
Cleaning wile you cook, especially if you live alone. Most times I'll have everything cleaned and put away, and leftover containers portioned out before I start eating. Things wash off easier right away, and most recipes have enough down time to finish everything (though I have occasionally had to microwave my own meal).
Heck, just cleaning in general, actually. Doing a little every day stops it from building up to the point where it seems like a monumental task you keep putting off.
Leave your house early enough so you aren't trying to make up time on the road.
Working safely. It only takes one second for something bad to happen to you and change your life forever. Leave from work the same way you came to work.
Pre-flight check on an airplane, including weather ahead.
This is gonna sound lame but...
...hugging someone until they are ready to let go
Edit: holy shit didn’t expect this to blow up this big. Thanks for all the responses and the gold... whomever you may be.
Changing the bed sheets, even if you're tired. Love when everything feels so crisp and clean!
Putting your seatbelt on. I've always worn mine but I was in a serious accident about 15 years ago where I have no doubt my seatbelt saved my life. I don't ever get in a car without putting my seatbelt on first thing.