I freeze all produce pieces that would normally be tossed out, and once there is alot, I boil it to make vegetable stock. Breen bean trimmings, brocoli stems, celery leaves, onion ends etc. Add salt and some bay leaves, and yo have a usalbe stock.
Another frugal kitchen tip--(grocery shopping) I'm sure you all do this, but thought I would throw it out there.
I make my grocery list based on what is on sale at the grocery stores. If something is on sale, and it is somthing I use alot, I buy LOTS of it and store it in my pantry or freezer (no--not frozen pizza

. Only go to the grocery store with the list, and only buy what's on the list. If by some reason a spontaneous trip to to the grocery store is warranted ( for one or two things)--don't get a cart--too easy to be tempted. I only go groc. shopping once every two weeks, unless there are really good sales, then a weekly trip is called for.
I also combine all errands so less trips into town are needed.