don'tbe, one of the better "obvious indicators" comes by a lot of study and experience and it is called a "gut feeling".
And that is when you look at a piece and say, ..... "That's a good one, don't know why, but its a good one".
don'tbe, there are so many "tricks of the trade" it might be best if you picked another item, then another, etc. to solicit opinions about. Like start a new thread titled
"??name??, .... Tricks of the Trade"