Penalty for performing melachah during "bein hashemashot", as Shabbat begins/ends, or as Yom Kippur begins/ends, so that only part occurs on Shabbat itself: Keritot 19a, 19b
Specific Forms of Work
Use of [non-life-saving] Medication; allowing it via the "Hoil" Principle: Shabbat 111a
Allowing chopping up vegetables and other vegetable preparation on Yom Kippur afternoon: Shabbat 114b, 115a
Allowing chopping up vegetables and other vegetable preparation on Yom Kippur afternoon where it could be used immediately after Yom Kippur: Shabbat 114b
Allowing chopping up vegetables and other vegetable preparation on Yom Kippur afternoon, if it is Shabbat: Shabbat 114b-115a