I, too, have used some of these tips; however, there are others that are new to this gal & I am "biting at the bit" to try them.
The one about the pastic wrap on the bananas intrigues me. I have, also, read/heard that bananas stay fresher when separated.
The tin foil wrapped around foods works with celery - I know because I have done that. However, since first learning of that idea, I have heard that it is best to not allow foil to touch foods. I tried wrapping celery in waxed paper & then in foil - that didn't work well at all!