Fixing the mind upon Shree Krishna is the perfection of
sādhanā
(spiritual practice), but immediately on beginning the path, we cannot expect to become perfect.  So, what should those people do, who cannot perfectly fix their mind on God?  Shree Krishna states here that they should endeavor to remember Him with devotion.  As the saying goes, “Practice makes perfect.”  This is called
abhyāsa yog
, or “union with God through repeated practice.”  Each time the mind wanders toward other objects and ideas, the devotee must strive to bring it back to God through remembrance of His Names, Forms, Virtues, Pastimes, Abodes, and Associates.
Jagadguru Shree Kripaluji Maharaj emphasizes this repeated practice in his instructions for
sādhaks
jagata te mana ko haṭā kara, lagā hari meñ pyāre
isī kā abhyāsa puni puni, karu nirantara pyāre
(Sādhanā Karu Pyāre)
“O dear one, remove the mind from the world and fix it on God.  Practice this constantly, again and again!”