Excerpts from Ghazali's Inner Dimention of Islamic Worship
Three grades of fasting
It should be known that there are three grades of fasting: ordinary, special and extra-special.
Ordinary fasting means abstaining from food, drink and sexual satisfaction.
Special fasting means keeping one's ears, eyes,tongue, hands and feet-and all other organs-free from sin.
Extra-special fasting means fasting of the heart from unworthy concerns and worldly thoughts, in total disregard of everything but Allah.
See not what displeases Allah
A chaste regard, restrained from viewing anything that is blameworthy or reprehensible, or which distracts the heart and diverts it from the remembrance of God. The Prophet, said: the furtive glance is one of the poisoned arrows of Satan, on him be God's curse. Whoever forsakes it for fear of God, will receive from Him, great and gracious is He, a faith the sweetness of which he will find within his heart.'
Jabir relates from Anas that God's Messenger, on him be peace,said: 'Five things break a man's fast: lying,backbiting, scandalmongering, perjury and a lustful gaze.'
Speak no evil
Guarding one's tongue from twaddle, lying, backbiting, scandalmongering, obscenity, rudeness, wrangling and controversy; making it observe silence and occupying it with remembrance of Allah and with recitation of the Quran.
This is the fasting of the tongue. Sufyan said: "backbiting vitiates the fast." Layth quotes Mujahid as saying : "Two habits vitiate fasting: backbiting and telling lies.'
The Prophet said: ' Fasting is a shield; so when one of you is fasting he should not use foul or foolish talk. If someone attacks him or insults him, let him say:"I am fasting, I am fasting!"
Hear no evil
Closing one's ears to everything reprehensible; for everything unlawful
to utter is likewise unlawful to listen to. That is why Allah equated the eavesdropper with the profiteer " (They like to) listen to falsehood, to devour anything forbidden" (part of Quran 5: 42).
Do no evil
Keeping all other limbs and organs away from sin: the hands and feet from reprehensible deeds, and the stomach from questionable food at the time for breaking fast.
It is meaningless to fast, to abstain from lawful food, only to break one's Fast on what is unlawful.
The object of Fasting is to induce moderation. The Prophet said 'How many of those who Fast, get nothing from it but hunger and thirst!'
Of what use is the fast as a means of conquering God's enemy and abating appetite, if at the time of breaking it not only makes up for all one has missed during the daytime, but perhaps also indulges in a variety of extra foods?
It has even become the custom to stock up for Ramadan with all kinds of foodstuffs, so that more is consumed during that time than in the course of several other months put together.
It is well known that the object of fasting is to experience hunger and to check desire, in order to reinforce the soul in piety.
If the stomach is starved from early morning till evening, so that it's appetite is aroused and it's craving intensified, and it is then offered delicacies and allowed to eat its fill, its taste for pleasure is increased and its force exaggerated; passions are activated which would have lain dormant under normal conditions.
It is therefore essential to cut down one's intake of what one would consume on a normal night, when not Fasting. No benefit is derived from the fast if one consumes as much as he or she would usually take during the day and night combined.
Look to Allah with fear and hope
After the fast has been broken, the heart should swing like a pendulum between fear and hope. For one does not know if one's fast will be accepted, so that one will find favor with God, or whether it will be rejected, leaving one among those He abhors. This is how one should be at the end of any act of worship one performs.
Taken from: http://soundvision.com/Info/ramadan/innerf.asp