I’ve always been cheap with postage stamps, without realizing it.
Until…I had a personal letter to mail and it was going to take a second stamp. I didn’t want to use another 34-cent one, so I went to the post office to get some 23-cent “second ounce” stamps. At which point I realized that the trip cost more than I was going to save.
I usually penny pinch on purpose, so it’s not a matter of catching myself in that, but catching myself NOT penny pinching, lol. (I have a drawer of various outdated stamps from past postal hikes. You’re likely to get a letter from me stamped with a combination of postcard and letter stamps from the last 5 years.)
I’m not much of a penny pincher. I often say “time is money.”
Normally I wouldn’t, but in this economy, it’s a necessity. 
I always make sure the lights are out if I’m leaving a room for an extended amount of time. Is that penny-pinching or reasonable behavior?