I swear I'm not a packrat! I think packrats are people who love to buy things and squirrel them away with no real intention of ever using them. I try to come up with creative ways to use less, and ways to use up things that people usually throw away. Some recent attempts to use less:
Sour milk---Makes the BEST pancakes! Anytime milk or half/half starts to get a little funky, I use it for baking. Homemade pancakes is a great breakfast, but we really love them for dinner. You can also use it in muffins, or to make my homemade "cream of anything soup".
Ziploc bags--I wash and re-use ziplocs all the time. The only ones I won't re-use are those that were used to store meat--those get tossed. I use foil to separate meat and I had been putting the meat in a ziploc bag so it wouldn't get water logged while it thawed. Lately I've started using leftover grocery store produce bags for this task. I usually wash out the ziploc bag inside out and hang it on my clothesline to dry.
Moldy/hard cheese--cut off the moldy part, grate the rest and put it in the freezer. Works really well in casseroles.
Old clothes--once they are just beyond repair or so stained that they can't be worn anymore, of course. I took an old flannel shirt and made Mama pads for me. You can cut apart old T-shirts to make cleaning rags or baby wipes.
Bubble Wrap--when I order textbooks or other things online, I save anything useful from the packaging. I NEVER buy packaging to ship books or stuff that I sell online.
Gift bags/tissue paper--I also save these so I never have to buy them to wrap presents.