The Rebbe's guidance to people going through financial difficulty:
Keep calm. Agitation doesn't solve financial hardship; calm communication and accepting the circumstances do more (IK 7853). Temporary hardship, for example from building a home, should not discourage (IK 5703). See also: פרנסה – ביטחון ודאגה.
Live within your means. Keep simchos moderate rather than extravagant; for example, a bar mitzvah celebrated locally allows more friends to take part and saves needless cost (IK 3092, 9782). Don't take on new commitments when existing ones are already heavy (IK 9718), and hold off on non-essential spending such as travel until debts are cleared and the family's needs are met (IK 6461, 8845). Expand a home only prudently (IK 9461). When investing, don't put in all your available cash or leave your account empty (IK 6022).
Stability first. Prefer a stable job over a quick gain (IK 6378). Try to stay independent rather than relying on others (IK 6445). Instead of giving up one's home because of debt, look for practical solutions, since one's living space affects wellbeing (IK 6397).
Tzedakah in hard times: don't stop giving; where full maaser is truly impossible, give part now and record the rest as a debt to be paid later (IK 6413, 10091). See: פרנסה – צדקה ומעשר.
Spiritual steps: sincere teshuvah, careful Shabbos observance, daily tzedakah, checking tefillin and mezuzos, and Tehillim (IK 4207).
For the financial difficulties of shuls, schools and communal organizations, see: Communal finances – Money troubles in shuls, schools and organizations.