Some of my tips may be influenced by travelling mostly around Africa. So, off the top of my head, and in no particular order:
- Always bring more than one credit card, and don't keep them all in the same place. I have had cards cancelled due to suspicious transactions a couple of times. Having only one card would have been inconvenient.
- Put a set of underwear in your hand luggage in case your checked luggage gets delayed or lost. Seems to happen every 7th trip or so.
- Don't fly Air France. Swimming is a better option.
- Don't pay with small change unless you have to. It's hard to come by in a lot of places, and you always seem to need it.
- Don't use a bum bag/fanny pack. Carry valuables under your clothes - and leave Grandpa's gold watch at home.
- Bring a bog roll - not all public toilets have them.
- Always, always, always be polite no matter how frustrated or angry you may get. (There are exceptions, but... you know.)
- If some official hints at expecting something "extra" (aka bribes) be calm, patient, polite and formal - and persistantly obtuse.
- Be open and friendly, but don't be stupid. Most people are genuinly friendly and helpful but there are some rotten eggs in the basket.
- ...and don't be paranoid. Ask about the local "dos and don'ts" - and don't do the don'ts.
- Ask the locals to teach you a few words of their language. It's a wonderful ice breaker - and you'll learn a few phrases.
- Read up on your destination before going - be prepared.
- Get up early. Less people, better photo light! And on safaris, better sightings
- Never say no to a beer
I do realise that the last two points may not always be compatible
Oh, and specifically for Africa: Bring some warm clothes. Africa is huge and diverse, the nights can be freezing cold. Africa has glaciers - bang smack on the equator. So yeah, bring that extra sweater.