I use NRR 33 earplugs and at least one white noise machine going, sometimes two, to avoid any noise pulling me back from near-sleep. The room is dark, but I wear a sleep mask just in case.
I'm averaging 1-2 hours with those. I'm doing the sleep hygiene thing, where I don't do anything in bed except (try to) sleep and sex. I think you're also supposed to just get up if you can't sleep, but if I do that, I just never sleep. I come back even more exhausted, and I'm still looking at the same damn wait.
Mental activity can definitely make it worse, but I haven't found a meditation/visualization sort of trick that really helped. The best I can do is psyche away the frustration and just... wait.
Alcohol/pot help maybe a little, but then I don't sleep deeply at all, always wake up really tired. I haven't tried prescription drugs. I'm told they have the same effect on sleep quality, and I don't want that. I do get much-needed good sleep once I'm there. It just takes too damn long.
I'd love to hear if anything's worked for you.