It is generally recommended to allow at least an hour between work and bedtime. If that doesn't seem possible, then it's time to admit that you are actually choosing to make it harder for yourself to sleep. Travelling in general puts a stress on your system, not only because of the time change, if you cross time zones, but also because of the disruption of normal routine. Pay attention to your routines, and see if there are ways to bring them along with you. Also, make the places you have to stay be as agreeable to you as possible, bringing a few things to make it seem more like home.
Sleep is the great teacher in the art of letting go.
It doesn't come when you try hard, it comes when you just let go and let it gently come over you. If you are awake and find yourself trying hard to go to sleep, then consider getting up and putting that energy into something else until you start to feel sleepy again. There are many possibilities. You can try getting up and writing down any dream you remember and in the morning you can learn from it , if you are so inclined. Or just write in a journal or read a boring book.