In addition to protecting your cards and not mucking prematurely, even commenting out of turn can cost you. This happened on my last Las Vegas trip:Nice!
I was under the gun with the queen and jack of hearts and limped. The cutoff raised, modestly, and the button and the big blind called. I called, too.
The flop was king of hearts/ten of hearts/eight of diamonds, giving me an open-ended straight flush draw. I checked. Cutoff bet. Button folded. Big Blind (who had at least $400 less than Cutoff and I each had) shoved. I called, and Cutoff made a weird raise, leaving me with $26 after I called. Thus, there was a substantial side pot.
Turn was the 4 of spades. I checked. Cutoff checked. River was the 2 of clubs.
Before I could do anything, Cutoff said, “Argh. I missed.” I hesitated for only a moment and then threw in my last $26. Cutoff quickly folded his ace of hearts/nine of hearts face up.
I lost the main pot to Big Blind’s set of eights, but I won the side pot with king high on the strength of my $26 river bet (and paying attention).