The Rebbe provides guidelines for Yud Shevat, urging Torah study, Basi L’Gani, Tehillim, tzedakah, farbrengens, and outreach. He encourages continuing these efforts beyond the yahrzeit, especially on Shabbat, and prays for the geulah and the revival of tzaddikim.
https://www.torahrecordings.com/rebbe/004_igros_kodesh/shevat/885