Jet lag? Never? I keep a time piece (usually my iPhone) set to my personal local time. My body runs strictly on the time I see on my time piece whether it is across the United States or overseas. This has worked for me when I worked graveyard shift. I have my body a local time and ignore distracions such as sunrise or other clocks.
In order to make myself sleep and get onto a new day-night cycle, I will take some sort of mild exercise so that I break a sweat. Then shower and sleep, get up in time for a light breakfast, and I am usually physically ready to go for a whole day without extreme fatigue. I hope this helps.