This one borders on just wanting to be crafty but I make my own envelopes. You can make your own postcards as well..I usually use random bits of 'found paper' or unwanted scrapbooking paper, rubber stamps, etc. to make my own postcards.
I cut my own bangs.
Sometimes I peruse the clearance rack at the grocery store.
There are only three authors books I buy (which I wait until I can either find at a thrift store or the sale section at the library) but other than that I just borrow books at the library.
Unless it's on sale I usually buy store brand food items.
During the winter (it gets cold here!) I put the thermostat during the day around 66 and at night I put it on 59 degrees. And when I'm not home I put it really low. I can't suggest what to put the thermostat for AC because I don't have an AC.
Unless I am actually using my computer/laptop I turn it off. It saves electricity & lengthens the life span of your computer.
Don't go grocery shopping when you're hungry :)
I only have a couple of store credit cards but if I buy something unless I get free interest (like Best buy does) then I pay off the balance that month. I pay enough internet on my car and home that there's no way I will more than I have to.
If at all possible combine your home phone, cable and internet service. You almost always save money. Or sometimes you can save money by eliminating one of them.