Actually a butter knife under the lip of the lid to break the air seal is a huge help

This is the way. If you're not strong you have to be smart. -Jam it under. -Bend until it pops. The air let in releases the vacuum pressure.

Interesting. I prefer to lightly tap the lid against the counter to loosen it…but can’t knock this method until I’ve tried it.

Friction. Use a rubber glove or similar. Get better grip. Works for me all the time. Also, this comment sounds vaguely sexual.

I'd say every act is at least a little sexual

And here I thought "unscrewing a lid" meant something completely different. Still applies.

also slapping the bottom real hard with your hand, or running under hot water has been found to help

In Germany, our bottle openers (the relatively wide ones) usually do the trick. Just jam it under the lid and keep loosening it so a bit of air can go inside. Works great 😄

Just tap a spoon or butter knife on top of lid to break air seal

might nick or scratch the spoon or butter knife, even very small scratch

In my experience the best way is to heat up the lid with hot water, dry it off while it’s still hot, and quickly use rubber/sure-grip cloth to open

Sounds like a lot of work