A: It is not a matter of offending them. You are the one who knows how they should be doing whatever it is you noticed being done wrongly. Since you have the superior knowledge, they should stop and listen to everything you have to say! You are a sage, at least where this one thing is concerned, and they should be soaking in your wisdom. Most people have no idea what they are doing and would love to have someone with a clue give them some advice. Educate them! They might get a tiny bit upset at first, but eventually they will realize the benefit of your advice and be very grateful. They may not say it out loud every time, but they will be thanking you in their hearts, praising your name under their breath, and keeping you foremost in their thoughts.