I agree with a lot of the advice in this thread, but also think there's some trial and error to figure out what works best for you. Personally, I try to leave the hotel curtains open when I get in the night before the redeye to cut my sleep short a few hours. I get up early and have a big meal, no coffee and avoid the gym. Take it easy, maybe walk around for a little while, then take 3 mg. or less of melatonin just before lunch time and aim for about a 6 hour nap and plan to get up a couple hours before van time, but set my alarm for an hour before van time. That way, if I get a good nap, I'll wake up early and have time for the gym, dinner, and coffee, but if it takes me a few hours to fall asleep, I'll still get good rest. Nap with an eye mask and earplugs, maybe play white noise from the phone if the hotel is noisy. I also bring a thermos (I really like Zojirushi) and try to get coffee downtown before going to the airport, in case there's no airport coffee available by the time we get there.