Well, the best answer is the one that resonates the most peace within yourself. However the first entry by scooter and the ever so serious Alex, by recommending Qigong is definitely a bull's eye, Taranis style. You could practice under a fig tree or practically anywhere...anyway peace of mind is the basis for concentration. Yo, fyi the Focus and Concentration paraliminal is DA BOMB!
Just for fun, the Celts didn't pronounce gh, dh, and some ch combos, plus the h was an action that changed the sound of the following vowel. So Bodhi becomes Boi, like the Latin for Celtic Boii, as in Bohemian(Boiimian)...As the rapper Flava Flav would say, "Yeah Boii!"
Much respect for the journey of self mastery... all the best on your quest! :-)
~Vegan Forever~