That ability is a tough one to figure out.  Questions like 'Whats the point? How do I help? Why me?.  I've had this little weird ability for about 20 years now and it confused and scared me for quite awhile.  I seem to attract 'quick' death and/or Coma spirits as well.

I never really 'heard' a sign, but felt the energy and followed it to the person.  Like you were saying...they just seem to stand out, you don't have to look to hard that's for sure.  It's like seeing a strawberry in a bowl of blueberries...it's just that obvious.  

Anyway,  I handle it by approaching the person and starting a conversation with them.  Most especially if I feel it will be an untimely passing.  Bring up life experiences and such.  Keep it light and let them do the talking.  It's strange because once you start the ball rolling, they just talk and talk.  The point that I am trying to make is that I get the person to remember all of their life abundances and happy things.  It's a tough thing to learn when you start, but get's easier and easier with each person  Let people feel like they are important and have accomplished and received so many blessings in their lives.  That's how I feel I help, because there is nothing more that I can do.  Then I tell them it was a pleasure meeting them and give them a hug filled with love and appreciation for having met them.  Remind them that they touched my life at that moment.  That's it and that's all.

That's just how I handle it...you may have a different way that makes you feel like the ability is worthwhile, and that's awesome too.

Just a quick sanity note though...if it get's too much or you just don't have time...this is what I do.  I say and send out energy of 'sorry, I just can't do this right now, can someone else help please'.  And then you go on with your day, that simple.

Hope this helps and remember to only do what you are comfortable with.  No bad things will happen to you if you deny or refuse the ability.  There are many others out there that are ok with taking over when called.

Take care, carollynnes

All I can say from my own knowledge is that those gifts are meant to be explored, and our fears are meant to be conquered.
The ability is a bit scary, because it goes against things that we don't understand. Kind of like - people who look different will scare us at times and we may feel guilty for being scared of them, but the fact of that matter is that that's something we don't experience everyday.
One thing I would like to add though, that that I do believe that with the "ability" we already can sense these things, they only grow greater if we work on what we enjoy/do best.
I believe you may have been shown where your strengths lie, and now it is your decision to get more comfortable with this, and prepare- you may also be shown something that will remind you later what we can do.
A lot to do with our abilities has a lot to do with our comfort zone. You can not see someone whose been abused, if you choose to cancel out the vision.
You know what you are able to do you may be told that you must learn to relax. To receive what is possible.
As far as helping people goes - I don't know how you could help.
Here is my personal experience, that you may consider, but not take to your own use for we are separate beings, and have our own way to go about things.
I like to know what is going to happen, but I can not if I choose to altar it in any way. If I choose to alter it, or give physical reality recognition of these things, something usually ends up going wrong.
I don't know how you would be able to help in this situation, unless you meditated on the idea of "how to help". Maybe you are meant to help others because they need to recognize these things but have been ignorant to their inner voice telling them something is wrong, but you must practice your way of approach.
If you feel so strongly you must help people, well -- you were shown one thing, but "how" is the next thing you must search.
These questions can only come from yourself.

Above all - I believe you know what you're meant to do, you were shown, and until you are ready to use it to your greatest-- you must become comfortable with what is "different" and scary and unusual to you. Emotions are barriers. Once you get past them you are open to a whole new world of opportunities.