Finding the Queen

When declarer is missing the queen in a suit, there are many techniques to use before resorting to a 50-50 finesse. 

If there is only one way to finesse, such as:KJ2 opposite A76  or   A765 opposite KJ43, the old adage applies:

"Eight Ever, Nine Never."  This means that with 8 (or fewer) cards in the suit, always (ever) finesse.  With 9 (or more) cards in the suit, never finesse (play for the drop).  So, in the 2 layouts above, finesse. With A8762 opposite KJ43, play for the drop (don't finesse).

It gets more interesting if you can finesse either way, such as:  KJ10 opposite A43.  There are many techniques available (such as leading the jack to see if they cover). Experts often can locate the queen by counting the opposing points and/or distribution.

The best way to play any of these suits is not to play them at all! Let the opponents break the suit if possible.