Recessed light fixtures can be a major source of heat loss, but you need to be careful how close you place insulation next to a fixture unless it is marked. "I.C."—designed for direct insulation contact. Check your local building codes for recommendations.
Recessed light fixtures can poke into the attic insulation and create a pathway for air leaks. Caulk around them from below with high-temperature flexible caulk.
Ceiling fans should rotate counter clock-wise in the summer (to generate a breeze downward to cool you off) and clock-wise in the winter (to cycle the warm air that rises to your ceiling.) Do not be afraid to run your ceiling fan in the winter. You can expect a 10-15% savings on your heating bill. You can save up to 40% off your cooling bill in the summer.