On the Ekadasi day, full fasting is the best. Otherwise, do not eat beans or grains. For details about what can be eaten and what cannot be eaten on Ekadasi are given at our web www.gokulbhajan.com and see under the EKADASI tab.
When breaking the Ekadasi on Dvadasi (which is next day of Ekadasi), during the breaking time mentioned, chant 'Om Namo Bhagavate Vasudevaya' 3 times facing east and then take grains. (The punya can be also given to or shared with any loved ones or ancestors by remembering them and telling their names before eating the grains.)
Why do we follow ekadasi vrata?
As all our acharyas are saying, the topmost reason to follow ekadasi must be to get Krsna bhakti.. All others may be the side benefits but not the main goal.