Done international at a few carriers (including Big D).
First suggestion: if you find your body can’t handle it (me), don’t do it. Bid off ASAP. but by all means try and see how you like it.
Second suggestion: when you’re in the aircraft bunk on crew rest, sleep without an alarm without a care in the world.
Believe me. The other pilots want their rest too. They’ll wake you up. (Personal note: couldn’t do this myself, fretted constantly about oversleeping.).
International: some love it. Some hate it. You never know until you try.