Reduce heating cost tips

Got new heating bill for last 2 weeks, 5800 kwh, $480, It is little bit high, wonder there is anyway to reduce heating cost?

1) By setting to 20 C will reduce heating bill by 5% - 10%;

2) turn the heat down to (such as 16 C compared with regular 20 C) when leave the house or sleep during night, would be great if install a programmable thermostat to setup schedule, it will save 15% on heating cost;

3) change furnace dirty filter regularly, normal once a year to make sure furnace function well;

4) open curtains during day time and close all during night to keep solar heating as much as possible;

5) heat yourself first then the house, put on a sweater, socks and warm slipper;

6) considering heat pump as source, will save a lot on heating;

7) solar solution is trend but investment is quite high