I hum to myself a lot and my husband hates this. It took me a while but I practically stopped doing this.
I also used to sigh a lot, until my older son pointed it out. It was during a period of my life when I was very depressed and dissatisfied, and I think I was literally letting my feelings out.
Now we need a thread about “what are the little things that people do that annoy you and you wish they would change?” 
I see some above that would drive me batty! (and am sure I have a few of my own)
@alh, that made me LOL
According to a holistic practitioner I knew, sighing isn’t stress relieving. It can change the blood oxygen balance, add stress.
My daughter pointed out to me that, instead of saying I’d like her to do something, I sometimes word it in the form of a question as if I’m just asking if she’d LIKE to do whatever it is. She had a really good point: if I want her to do something, I should just request she do it! I’ve tried to change but sometimes I’m unaware I’ve done it until she asks if I WANT her to do xyz or am just suggesting it. Usually I want her to do it. It’s a process…
As long as it’s asked respectfully, I don’t mind constructive criticism from a loved one.
Just thought of another one…I’m not particularly critical but once in awhile I’d notice something, such as a missing button or something on one of my D’s jackets that would suggest it need to go to the dry cleaner for example and I’d mention it. One of my D’s asked me to not say something at a time when she couldn’t do anything about it. Great point! Should I have a desire to mention something like that now, I always wait until the person’s is in a position to do something about it (not wear it, clean it, fix that bump in her hair that I know she’d want to know about), etc.
My son pointed out that I chew loudly. I’m working on that one. But then, again, he hates the sound of anyone eating.
I would say sighing only adds stress and changes oxygen blood levels if you don’t breathe it back in again…
and I used to sigh a lot too (and yes, family pointed it out)–surprised it got mentioned!
My younger daughter told me that I hum when I am happy, which I never notice before. She likes it when I hum even though I am not a good singer.
Every xmas my sister will find a phrase my brother or I would use a lot, and she would point it out to us. My brother and I would try to correct it, but then we forget.
The person complaining about a sigh might appreciate being spared the opinion not being expressed. D stated she hated my sighs as she was learning to drive. It was painful for both of us and I was trying very hard to not be negative about her driving.
A friend I was visiting in another state mentioned that I have a very loud speaking voice. I am trying to watch that tendency. Working with the elderly, as well as friends getting hearing aids in recent years has led me to over compensate.
I am trying to work on posture, after having my slump pointed out. Not easy to remedy.
To say "yes"instead of “yeah.” I slowly changed to saying “yes.”
Walking with my hands shoved into my pants pockets. Took me years to get rid of that habit after I saw someone imitating me & my walk.
I’m trying to break my husband of that habit, since that’s what contributed to his fall on an uneven sidewalk and subsequent visit to the ER. Because his hands were in his pockets he didn’t have time to get them out to break his fall. He ended up falling on the side of his head, breaking his glasses, and just missed cutting his eye.
I have a habit of not completely closing the bedroom closet door and kitchen cupboards and drawers. I leave them a tiny bit ajar. It drives my husband crazy and I’m better about closing them now.
I do lots of annoying things, I talk too loud and say sorry too much.
You know what, it’s super annoying when people point these things out. Yea I get it, it’s annoying. You do annoying things also. I don’t point them out. It’s called being nice.
This thread was driving me a bit crazy. I do hate it when people point out what I’m doing wrong (and it’s a lot). Deal with it.
But if I have something in my teeth, point that out.
Sorry, D’s ex, every time he saw me, he told D what I was doing wrong (annoying trait) It was his way of controlling her (narcissistic person) and keeping her away from us. I hated it before when people pointed out what I was doing wrong. Now I’m even more sensitive to it.
In the old days, when someone asked me how I was, I would say, “I’m good, thank you!” Then I worked with a woman who would always say, “I’m well, thank you!”
She was right – “good” refers to my behavior, whereas “well” refers to my state of being. So now I answer with “Well.” No one pointed it out, but I kept hearing her say it, and I realized it made sense.
I am a much bigger a-hole when overtired: irritable, confrontational, sarcastic. My wife has made this visible to me over the years, and it really does stop me a little when she points out a sleep deficit in conjunction with poor behavior. (OTOH pointing it out when I am not tired or when there’s an actual issue makes things worse, but we’ve been together for a few decades and have these parameters worked out pretty well at this point. 
Oh, and when I was in college a friend pointed out how often I finished other people’s sentences for them. Even allowing for the fact that I was frequently right, I used it as a segue to start talking before they were done and that made it worse. I struggle with both to this day, but at least I’m aware and apologize often.