If you want to "blend in", try and find a t-shirt with some nonsensical English phrasing on it ("fashion pirate"... "world car race championship") to go with the obligatory tiny speedos
Get some over the top Oakleys that make you look like a cyborg
A few sit-ups wouldn't hurt either.
Try and match the local hand gestures
A few years ago a guy sitting about ten feet from me had all of his stuff stolen because he fell asleep
word, a few years back, after an 18 hour bus ride, I fell asleep on top of my bag on the beach in Salvador. Woke up to 3 dudes in rather fetching speedos pulling it from under me. At that point it's usually best to just let it go.
You could ask someone 'trustworthy' to watch your things, but how about one step further? Ask the most trustworthy
and attractive looking person to watch your things
Some people leave their stuff with a barraca owner too