Be on guard at the end of [a Fast]. Very often the more conscientious among the faithful make real efforts to keep the fast, both with regard to the dietary disciplines, and with regard to their inner life: contending with the passions and thoughts, avoiding and resisting temptations, spiritual reading, prayer, preparation for confession, more frequent reception of the Holy Mysteries, etc; but then in the first hours of the feast itself they completely lose an the profit they might have gained by abandoning all that they have so carefully practised during the fast. It is true that we keep the feasts as times of rejoicing and that we are released from the discipline of fasting, but we should be careful not to do this is such a way that we abandon every appearance of Christian struggle.
Try to remember to keep Pascha holy. This might seem an odd and unnecessary tip, but it happens that at all the greater festivals, and particularly at Christmas and Pascha, one finds that after the fast, there is a temptation simply to let go. True, we can start eating non-lenten products again, but this does not mean that we should plunge into gluttony or drunkenness. The church services are shorter and the typicon less demanding, but very often one notices that there is a veritable apostasy after a major feast. If we have gained anything spiritually in the course of the fast, let us try to hold it fast and not to lose it heedlessly. In this way, step by small step, with each fast and each feast we shall be able to make some little progress spiritually, using each as the rungs of a ladder.
—From OrthodoxInfo.com