If you're away for a few days at some point, read the meter to get a estimate of how many units your home uses when it is not occupied. You can then gauge how much of your bill is due to daily activity. This might help you zero in on activity vs overheads you can reduce.
Other little things that may shave off a few baht
1) Keep the refrigerator door closed more
2) use the washing machine less, do larger loads less frequently, check what type of wash cycles duration/water temp you use, let the sun do the drying use less spin speed/time
3) If you're going to cook, then possibly cook meals for several days at one time. Allow items from the fridge/freezer to defrost or reach room temp before heating/cooking