Here’s the thing.  People who are stressed out already know it.  They may even have an idea on how to relax, but something is blocking them.  Many know at least some of the sources of their stress.  With all of that, there’s really no reason for me to do a list where I tell people how to eliminate stress.  Works differently for each person.  Instead, I’m going to give some ideas to those who are around a stressed person and may to either help or at least not make things worse.  Yes, your hearts are in the right place, but that doesn’t mean much to a person who is about to explode like a Psyduck with a migraine . . . Look it up.

1. Just look at the picture.  Seriously, you aren’t going to get very far by telling somebody to relax.  They won’t suddenly snap out of it and immediately rid themselves of the stress.  It’s more likely that this will upset them more because it will come off as patronizing.
2. Learn to read body language in order to gauge stress levels and if things are getting worse as you interact.  Tension rising in the muscles, high rate of averting one’s eyes, inching away, twitches, and changes in voice tone are some examples.  If it is getting worse then you’re probably making things worse.  Oh, you’re texting and it’s impossible to tell?  Yes and no.  If the person takes long breaks between answers or only gives noncommittal, one word answers then communication is breaking down.
3. Many times, you don’t have to say anything.  Much like with anxiety and depression, you can help out a lot by sitting there and listening.  Do not respond unless asked for something.  Interrupt only for clarification and then let them proceed.  Show that you are interested in hearing them speak about what has them upset.  The release may be enough to push the rising stress back.
4. If you know the person is stressed because of a situation or certain people then don’t force them to face it.  Do the opposite in some cases.  Invite them out for time away from what is plaguing them.  Catch a movie or get some ice cream or anything that is relaxing.  Talk about anything they want.  If they don’t want to go then accept that and don’t make them feel guilty.
5. Some people have various hobbies that they use to unwind and these are very important for those who get stressed easily.  Show interest in this, but do not push too hard and ruin what is a good thing to them.  Trying to involve yourself or others in the same activity or giving suggestions on how else they can do it can infect their relaxation zone/object.  For example, I use jigsaw puzzles to relax.  A person who will remain nameless has kept trying to get someone else involved in my hobby to create a bonding experience.  This upsets me and makes it feel like my ‘happy place’ is being stolen or turned into a chore.  Another issue is when someone sees the puzzle I’m working on and decides to help.  Again, there’s a sense of violation.  (This could also be caused by anxiety.)
6. If someone in your life decides to take a mental health day from work, DO NOT tell them why it’s a bad idea.  They are already aware that it removes a potential sick day that they may need for a physical illness.  By pointing out the risk, you’ve actually made them waste a day that was intended to be one of recovery.  Also, don’t see it as a chance to hang out and get things done.  They took the day off for themselves and not to be given chores or for your entertainment.
7. Do NOT take offense if a stressed person tells you to go away or leave them alone.  Even if it’s blunt and rude, you have to understand that they are under pressure and are reaching the edge of a mental cliff.  You may have pushed them too far by accident and that’s why they’re lashing out.  It could be that they were at this point before you arrived and you were simply unlucky.  Just wish them a good day and, if you want, let them know that you’re around if they’re up to talking later.  They might not take you up on that offer and you shouldn’t push, but it could help for them to know.