What is Lojong?
Both Mahayana and Theravadin Buddhism has the tradition of taking the eight precepts for a full day (sunup to sunup) for laypeople. In the Theravadin tradition laypeople must take these precepts each time from a monk. In the Mahayana, the first time they take the eight precepts they take them from a monastic and then they can take the precepts on their own.
Taking the precepts accrues a great deal of merit making it a good practice for laypeople.
The precepts themselves are the five precepts – refrain from killing, stealing, harsh speech, alcohol and intoxicants (except medicine), and refraining from sexual activity and additionally refraining from singing and dancing (entertainments, so no TV, but also makeup and perfume), avoid high beds and high seats (this is a reduction in pride and exercise in humility but you can sleep in your normal bed), and avoiding eating after noon (and in some versions eating once and finishing eating before noon as well).
If you are new to the points of Lojong mind training, the following 2 links offer a place to start. The points of Lojong mind training are extremely practical, and very helpful in daily life and practice.
What is Sojong?
Sojong is the act of following one day ‘lay’ precepts and is a purification ritual.
Many Buddhists follow Sojong on holy days, and full, half and new moon days. The precepts are the same as monastic precepts, except instead of taking them for life, the lay practitioner takes them one day at a time. They are a very effective way to help train the body and speech of a lay practitioner, which will help with one’s meditation practice.