Don't Be So Quick to Overruff
this was the position, when i (east) led the K of clubs. declarer ruffed with the 7, and you over-ruffed, presenting declarer with 2 tricks regardless of what you lead back (you actually led the J of spades, declarer pitching her diamond).
look what happens if instead, you pitch your spade when declarer ruffs my club. if she then leads her diamond, you ruff low and i over-ruff with my Q, and you make the last 2 with your A10 over declarer's K9. if she leads a trump instead, she's doomed as well. declarer is held to 1 trick of the last 4, instead of the 2 tricks she actually made, enabling her to make her contract of 2H.
remember this theme, and make mental notes. in some cases you will find yourself endplayed after the over-ruff as you did here. in other situations, even though declarer still remains with more trumps than you, your refusal to over-ruff leaves you with a double-tenace, entitling you to three trump tricks rather than two. situations where it is more advantageous not to over-ruff declarer are really quite common, and the right play means an extra trick.
Short Suit Leads
If pd leads a short suit, and you're torn between it being a singleton of a doubleton, it's probably a doubleton and you need to hold up your A. While your probable fear that pd will assume that declarer holds the A, and therefore eschew going for the ruff when he regains the lead, a good pd (me?), will appreciate that you may be holding up a round and act instead on your attitude signal at trick one. remember, it is more likely (probability-wise) that you hold a doubleton than a singleton.
The Lead of the Queen
Clarifications & Reminders:
--- The lead of the Queen @ NT asks: 1st Priority -- DROP the JACK; 2nd Priority -- show attitude.
--- The lead of the Queen @ suits *says* you have the King as well. If 3rd hand plays the Jack, it should show either the 10 or a singleton, i.e., it is safe to underlead the King on the next trick. This is the same when the King is led and 3rd hand plays the Queen -- it shows that 3rd hand can win the next trick.
To Moyse or not to Moyse
Unless you are scrambling (where one pd has made a demand takeout to one of his suits, e.g. michaels, unusual NT, etc.) or the opps are already dbl'ing you all over the map, don't be looking to stop on a dime in a moysian at the 3-level, ESPECIALLY in a suit that hasn't already been named.