Mindfulness is much more than breathing exercises.

Mindfulness encompasses being mindful of what you are doing as you do it. It means you focus only on what you are doing and not allow other thoughts to enter while you are doing that activity. It's okay if you can't focus on breath for long, the idea is to block any other thoughts. That's the basis for mindfulness skill.

Right now I am typing this post to you. I'm blocking out the thoughts of the tv ad that are trying to make me listen to it, I'm blocking the thoughts of the coffee that calls to me {big breath} ahhhhh I want to italicize a few words here ... I want to give you support without entering into the post myself.

This means you stop multi-tasking.
No more ruminating about things in the past, or things you want to get done once you're done with "this" project. You focus only on what you are doing ... if it's preparing a meal, then you are thinking about the pot you wish to use, then the food you are washing or spicing ... then you focus on the stove or oven and setting the temperature.

OR such as You are driving in your car. You don't have the radio on to fill you mind with chatter or music that can distract you. You focus on driving...the car in front of you that breaks all too often, you check each mirror every 7 seconds like the experts tell us, you feel the steering wheel in your hands...you breathe calmly. You block thoughts of what you're going to tell the T, or how late you might be if you don't catch that light...etc.

Get the idea?

Learning to focus is the reason for the breathing exercise. Don't sweat it if you can't fully do it yet... you'll get there. It's a learned skill.