The beginning of astronomical (and in come climates, meteorological) Spring represents a critical turning point in the agricultural cycle. Livestock reproduction is in full swing, milk is now more plentiful, and the disappearance of snow and ice mean that the earth is now accessible and warm enough to prepare for the sowing season.
Outside the domestic sphere, animal and plant life are also in the midst of a dramatic change. Wild animals have already (or will soon) produce their young, and plants are beginning to bud and bloom. Longer days and warmer weather have arrived or will very soon, and that means that the dangers of winter have nearly passed. The Spring Feast marks the beginning of a focus on fertility and new life.
Across the spectrum of Indo-European cultures, celebrations of the Spring Equinox seem to vary in importance. The Ancient Greeks celebrated the God Dionysus by opening new jars of wine, the Romans observed several feast days that tend to focus on vegetation deities, and the Celts mark the equinox through their mythological cycle. There is some evidence that the Norse celebrated the spring equinox; such an observance makes sense considering the importance (and dramatic nature) of the solar cycle among the Scandinavian cultures.
I lived most of my life in the American South, where the weather for the spring equinox varied from very warm to cool, but you could more or less count on the trees already beginning to bud, noticeably longer days, and signs of animal life all around. My experience of Spring in the South has heavily shaped my own practice, and even if the time of fertility and warmth are not as pronounced here in the Midwest, the psychological effect of the season remain intact.
Feasting has always been my favorite part of the Spring Equinox, whether that means a big Easter dinners with my family or having a meal with my fellow Neopagans. From a ritual perspective, my devotional practice aligns well with the Norse celebration of the solar cycle (or at least it aligns well with what has been speculated about it) and the Roman preoccupation with vegetation deities. Above all, there is a distinct notion of awakening, and that is always my guiding principle.