I avoid caffeine prior to flying and during the flight. Eye masks and earplugs aren't my thing but earbuds help with white noise if that's helpful for you. I agree with loose shoes you can slip on and off in need be. I've heard melatonin works well but have never needed it. I usually use the head clips that are usually on the top of the flight seats where your head sits. You can usually snap them towards the middle of the seat to keep your head straight. If not I just roll up a jacket or blanket as a pillow. I think sitting near a window helps too because no one is needing to wake you up and get past you.