Use the lamps with low consumption, they enable you to save 80% of your consumption.
Do not forget to extinguish the bulbs lit unnecessarily.
You point out especially that daylight does not cost you anything, then profit to the maximum.
Make a good choice and will be able to adapt your lighting to your needs, you there will gain in comfort and will realize savings.
The electric heating is expensive; if you cannot pass some to you, try to limit its use.