Pack when you are sober and stay sober whilst packing!
I’ve said this jokingly but it rings true. Do not pack when you are hung over! You may forget essential items which you will then pay for dearly. It’s so important to be in top form when packing particularly if you are going to another country. Things like medical insurance, essential clothing, passports even underwear can be forgotten! I am speaking from experience. Take time to pack and then go out and have a good time.
Pack light! Whether you are flying or are on a road trip – Pack light! It’s easier to move about with small luggage bags. If you have the opportunity to do a stop-over, heavy luggage may hinder you from taking sneak peaks at certain points. I always travel with almost nothing so that on my way back I can fill up my suitcases to the brim and still be within my luggage limitations.