Commenting of numismatic collections... Do's and don'ts.

You probably found yourself in situation when your fellow numismatic friend asked you to comment his numismatic collection and instead of showing you some numismatic “jewels“, he (or she) showed you a number of cheap, low graded coins or banknotes... What should you do in that case? What kind of comment should you give about numismatic collections you don't like? Should you be brutally honest... or maybe you should put yourself in your friend's position and do something different? If you have such issues, p