Be careful with taximen... :-/Feel naked
Athough I've been stolen twice in three days (unusual to me, I'm travelling around since 30 years, without any major problems, excet in Cambodia... And Bolivia), these countries are just amazing. Beautiful, fascinating too. Take your time, avoid to take plane. Not for safety reasons, but just because sightseeing worths it. Going from Peru to Bolivia by coaches and boats on Titicaca's lake is unforgettable.
Maybe it is better to speak in Spanish and to avoid english. For most of locals, english-speakers mean americans (Gringos as they say).
And tell me if you need more specific informations,