"Regarding thinking of Krishna at the time of death. It is stated in Bhagavad gita 8th chapter as follows; abhyasa yoga yuktena/ cetasa nanya gamina/ paramam purusam divyam/ yati parthanucintyan (BG 8.8). He who meditates on the Supreme Personality of Godhead his mind constantly engaged in remembering me, undeviated from the path, He oh Partha is sure to reach Me. The proccess for remembering Krishna is very easily done by chanting Hare Krishna Maha mantra. How one should think of Krishna, that is given in the next verse: 'One should meditate upon the Supreme Person as the one who knows everything, Who is the oldest, Who is the controller, Who is smaller than the smallest, Maintainer of everything, and Who is beyond all material conception, Who is inconceivable, Who is always a person and luminous like the sun, and Being transcendental, beyond this material nature.' So Krishna is not something impersonal or void. So you should read my books and try to understand the nature of Krishna the Supreme Personality of Godhead, then it will be easy for you to think of Him."