I think that meditation works best in a quiet spot, with the computer turned off. The goal for me is to not have thoughts, other than on my breathing. Whenever other thoughts creep in, I recognize that this is a thought other than breathing, so I let it go and get back to the breathing.
To do a deep diaphram yoga-type breath, have your mouth closed and teeth a little apart, with your tongue lightly on the roof of your mouth just behind your front teeth. Your stomach/diaphram will expand on the in-breath, and will go back (towards your back) on the out-breath. Breathe into your stomach, then your rib cage, then your chest, expanding and filling each area. The out-breath goes from your chest, then your rib cage, then your stomach.
I like to add the three locks; throat, abdomen and root (engaging the pelvic floor). After the out-breath, lock the throat lock and let the next breath collect itself. Then breathe in to your stomach, rib cage and chest. Hold the breath while tightening the root, stomach, then throat locks.