With a Slavic language as my first, I generally feel like adding “please” or “thanks” makes a request canned-polite; essentially it distances the speaker from the receiver. That said, the effect could be adjusted with carefully chosen intonation.

Often a direct request would feel friendlier, unless receiver is particularly insecure/on the defensive. Sandwiching it between appreciative words is most foolproof, but I find it time-consuming to do in a genuine way.