30 Second Advice No 6: Be A Navy Seal!
The Navy Seals have a motto –
Two is one, One is none.
Embrace this. Use it every day and make it your mantra. You won't use it in the “I've only got one grenade left” sense, but apply the principle to everything that you do when you are travelling.
- don't let your phone go flat. Do you really want to have no access to call or find your hotel when you get there and it's all locked up.
- always have enough money that you can buy a ticket to anywhere. Sometimes you just need to get away from where you are and sleeping in a train station because you can't afford the sleeper (and that's all they have left) isn't the best option.
- have a local data sim, or make sure your home sim can be used for data in an emergency. I've had occasion where my cards (yes plural) wouldn't work and I could turn on my data & send myself money via Western Union that I could pick up immediately.
So like two is one, one is none, think about the possible consequences of being out of money, battery, data or anything else that might matter.