Pack earplugs in your carry on, try to be tired beforehand and if you are not going alone pop a sleeping pill after take off. I've done that journey a few times, isn't pleasant. Europe has the same kind of stuff in the shops as USA (assuming that's where your leaving from) so packing a lot of stuff like shampoo, shower gel isn't needed, take sample bottles to do you until you can shop. If you're going to UK pm or email me, from there so would be happy to give advice.