Documents...probably not what you are thinking but something I am pretty anal about....let me explain...please!
I don't mean visa's or passports (lets file them under the 'V' post) but I mean self-made documents. Whats that you say? What the 'eck am I talking about?
As a paranoid solo traveller I have a lot of print outs and these are my compass on my trips and what are they? Print outs of room bookings, printouts of tour bookings, printouts of pre-booked tickets, printouts of boarding passes.- I am seriously anal about this, I keep them all in my document wallet that matches my passport cover (oh dear, someone stop me!) and they have to be in the order that they will be needed. As I use one it goes to the bottom of the pile! I wouldn't cope without doing this. I just know it.
How do I know? I booked a hotel in Paris on my return from Marrakech and I forgot this vital piece of information and accompanying map. What happened was I got lost searching for the hotel that was five mniutes from the station, I asked someone who said this way, got lost again asked someone, who said this way, got lost again and this continued as I roamed the streets of Paris from 10.30pm until midnight with my suitcase and no Hotel information other than its name and a mobile phone with a flat battery!
I was very fortunate to meet a lady walking her dog, she was quintessentially French in every way and offered to drive me to my hotel in her mini, she ran up to her apartment to put her dog in and picked me up and we found the hotel. She told me if I was a male she wouldn't have taken me in her car! lol I was very lucky that she found me and she spoke english and was so kind,I was extra lucky because the night before it had been pouring with rain.
So it is very important to have hard copies because you never know when you battery will be dead, and you might not be in a wi-fi area.