[StavrosK]

In Greece, saying "please" can sound condescending. You pretty much want to avoid saying please, and politeness comes from the phrasing. "Can you bring me a glass of water" is the polite version of "bring me a glass of water", although the latter is also usually made polite by adding "re" (to friends) or adding "a bit" ("bring me a glass of water for a bit", it doesn't translate well).

Saying "please" to anyone you're even slightly familiar with would be at least weird, and in many cases condescending and offputting.

"Thanks" is somewhere between the US and India, where you don't thank everyone all the time, but do thank people who've done you a favor, or in service settings, people who have been good to you (good servers/shopkeepers/etc).

[harperlee]

In spain we have a mix of both; although it is very normal to say it formulaically to e.g. a shop clerk, we are also very often very direct and don't use it, just using tone or phrasing - and foreigners (including spanish-speaking ones) are usually shocked by how rude we seem to be.

[StavrosK]

I've found that Greek translates pretty much exactly to Spanish (culturally and linguistically), so I just say "puedes traerme <x>" or, at most, "quisiera un <x>".