One of the mistakes that new players make is when they have a combined 10-card holding missing the king, they try to drop it instead of finessing. I don't remember the exact percentages, but it's considerably better to finesse.
Bridge has lots of great colorful names for various plays. One of them is called the Rabbi's Rule. It says when the king is singleton, play the ace. You can even buy a tee shirt from Zazzle that sports this whimsical advice (see here).
Playing against the robots recently, I made a takeout double of 1♥ and the robot's partner raised to 2♥. My robot partner passed, and the first robot rebid 2NT. I doubled again, and it went all pass. Here are the two hands from declarer robot's perspective (rotated) after I led the ♦K:
I switched to the ♣9 and my robot partner won the king. He returned a club to the queen and my ace. I continued with the ♣J and 8, then took the setting trick with the ♦K and exited with a low diamond (the club suit blocked).
The robot declarer won that and led the ♥7 to his ace, dropping my king, ouch.
Here are all four hands in their original position:
I don't know how the declarer knew to drop my king as I'm more likely to double again with a void than a stiff king, no?