Those persons who are serious about the ultimate benefit for the soul will never eat grains on the Ekadashi tithi. According to the instructions of Lord Vishnu, every kind of sinful activity that can be found in the material world takes its residence in this place of foodstuff (grain). Whoever follows Ekadashi is freed from all sins and never enters into hellish regions. If one doesn’t follow Ekadashi because of illusion, he is still considered the utmost sinner. For every mouthful of grain that is eaten by a person, one receives the effect of killing millions of Brahmans. It is definitely necessary that one give up eating grain on Ekadashi. Especially since even if one by trickery follows Ekadashi, all of his sin becomes destroyed and he very easily attains the supreme goal, the abode of Vaikuntha.Rules for Ekaadashi
You should recommend the avoidance of mixed Ekadashi and the performance of pure Ekadashi. You should also describe the fault in not observing this. One should be very careful as far as these items are concerned. If one is not careful, one will be negligent in executing devotional service.
Vratas – what to do / austerities:
Specified foodgrains and beans (pulses) as foods that must be avoided on Ekadashi. One may use spices for cooking, although mustard seeds should be avoided. You should not use powdered asafatoeda (hing), since it (generally) contains grains. Sesame seeds are also to be avoided, except on Satila Ekadashi, when they may be offered and eaten.
Do not use any cooking ingredients that might be mixed with grains, such as ghee that has been used to fry puris, or spices touched by hands dusted with chapati flour. There is absolutely NO doubt about what is NOT permissible to eat on Ekadashi. ANNA-grains.What we could eat -“Fruits, Roots, Nuts, Milk”. If you stick to these types of foods you should be fine. Of course the sure way is to fast completely. Water of course can be taken. Except if you wish to do Nirjala.
Someone who is very strictly observing Ekadashi should avoid all spices except pepper, rock salt and cumin. He should also eschew certain vegetables, such as tomatoes, cauliflower, eggplant, and leafy vegetables.
Dvaadashi (the day after ekaadasi – the day of breaking the Ekaadashi Fast):
(To observe Ekadashi properly, one should strictly observe the breaking of this fast.)
One should break the fast after the sunrise of the dvadasi, after the first quarter of the dvadashi tithi has passed, but before the dvadashi tithi has ended. After taking morning bath, one should offer the upavasa to the Lord:
Oh Kesava, be pleased with this vrata performed by one fallen in the modes of darkness. Oh Lord, bestow your glance of knowledge upon me.
Sometimes, due to the manner in which the ekadashi tithi and the dvadashi tithis are positioned in relation to the sunrise (there are six different cases), the vrata is observed on the dvadashi and the fast is broken the next day, the trayodashi. Such a fast day is called a mahadvadashi, to distinguish it from a regular dvadashi, which is the day to break the ekadashi fast.