Just a little tip, or pointer, for those who are physically able to fast, but who may find it especially difficult.
Entering a fast in a state of dehydration (a state many of us habitually live in) makes a fast far more difficult. The bigger difficulty in fasting actually comes from thirst, rather than hunger, though one may not recognize the difference in symptoms.
However, if one keeps his body properly hydrated on a daily basis, then, when the time for a fast comes, going without food and drink for 24 hours is not the burden it is when the body is already in need of water at the onset of the fast.
This one simple thing can make fasting a much more spiritually meaningful experience.