Mindfulness is a technique for ensuring your mind can cope with anything.
Its calming. It increases your focus. It increases your clarity.
What is more it was discovered by Buddhists - pretty calm people aren't they? Maybe this is why!

What is it?
Simply put, mindfulness is a technique for detaching from your thoughts, while staying awake and alert in the present moment.

If you can, each day, in a spare moment, simply stop. Observe your thoughts. Notice what you are thinking about. Do not try to stop your thoughts. Do not judge them. Just simply watch them, like watching a television or like watching birds land in a tree and then fly off again. They will rise and float past, like bubbles going by, or clouds passing by in the sky. Let each thought happen and let it fade away until the next one. 
Try to stay awake and present in the moment while doing this. 

Practice makes perfect. In time you will be able to achieve this state rapidly.

Level 1 mindfulness

If you can achieve the ability to watch your thoughts without getting involved in them, then you have reached the first level of mindfulness, according to the EMF definition. Try to increase the length of time you can do this each day. In time it will become a habit.
Notice that between each thought there is a gap. With practice, you can widen this gap.
Now do the same technique with feelings as well. 
Soon you will find that an incredible sense of peace appears within you.

Level 2 mindfulness

We call level 2 mindfulness the ability to maintain a state of mindfulness while events are happening around you.
So, perhaps try to do your mindfulness technique in the living room or kitchen. Or in a park. 
See how long you can sustain it. Try it when eating or cleaning your teeth.
After a bit of practice, you will find that even the events around you become just like your thoughts. They come and go. You do not have to react to them or follow them. In fact your reaction to these things becomes a choice.

Level 3 mindfulness

You will have reached level 3 if you can maintain a mindful state while walking in the street or doing the shopping. 
The more practice you do, the longer you will be able to sustain this and nothing outside will be able to affect you.

Ahhh.. peace.. :-)