I sympathise if the OP has an issue with jet lag... don't we all! And yes, trying to use natural light to reset the body clock is a tried and trusted technique. But I am doubtful of the benefits of trying to do it whilst in flight! Others will be on different body clock times to you. Also, is it not unnatural to be exposed to so long (or short) a period of daylight or night time that flying long-haul creates (depending which way you travel) so just when you should be closing the blinds or not is actually difficult to ascertain until you stop travelling. It is a bit of a moving target. So it makes much more sense to start your body clock reset when you arrive at your destination.
Of course, if you are travelling across many time-zones for an extended period of time then it may help trying to keep your body on one time-zone sleeping and waking as best you can to your home zone but that must be very difficult. There will be times when sleeping is impossible, when you want dinner and breakfast is served and when you want to stay awake when others want to sleep. I am doing a Round the World trip in 8 days in a couple of weeks. I did entertain the idea of trying to stay on GMT but concluded it was just impossible.
Best to just enjoy the flight, try to sleep if that is what you feel you want to do or not as you feel and then when you arrive at your final destination do the body clock reset thing.
Personally, I close the blind when I want to watch the IFE or when the sun is bothersome. The rest of the time it is up as I enjoy the view. Am I selfish? I don't think so. It is just how it is... windows seats control the blinds. There are times with the sun shining in when I couldn't survive with such a bright light and so if I couldn't control the blind I couldn't sit in a window seat.