This is the method I use which I got in part from reading about lung exercises.
The technique:
1.) Expell all air from lungs.
2.) Take very deep breath of air, filling from the abdomen up.
3.) Expell all air from lungs.
4.) Fill lungs to 2/3 their capacity from vaporizer, filling from the abdomen up, drawing from fast to slow
5.) Fill rest of lung with air and if applicable remove vaporizer from heat source, continuing to draw off of the vaporizer (in order to cool vaporizer, stopping vaporization when not in use).
6.) Hold breath a moment.
7.) Inhale one last bit of air.
8.) Hold breath a while (as long as comfortable/possible).
9.) Exhale slowly and controlled through the nose.
Works well for me and everyone I know!