3. Speaking of laundry...she insists on using the recommended amount of liquid detergent in the washer. There are basically 4 adults living in our house and our clothes are not that dirty. I haven't seen a grass stain in about 7 years. Not sure how many times I've told her "just put in half a cap...these clothes aren't filthy." Nope.
They cost a little more up front, but those laundry detergent pods are great for this. We used to go through a box of detergent every couple of weeks -- just two of us, mind you -- because she'd fill that measuring scoop to the brim, despite the fact that I had taken a Sharpie and marked the line for a regular, non-crapped-in load of laundry.Since I switched us to pods we buy a box maybe once a month now. I'd estimate we save ~30% on our detergent costs.
My wife has this problem with dishsoap, and formerly with dishwasher detergent. When we used liquid dishwasher detergent she would overflow the compartments where you squirt it in, wasting a bunch and leaving residue on everything. We solved that problem with the packets. Where the huge Sam Club sized liquid would last a week, the packets last forever.
We still have the same problem with dish soap. I swear it is a 50/50 mixture of water and soap when she does the dishes. She squirts it in while the water is running and I can count to ten while she is squeezing the bottle. It's insane. Most of the stuff goes in the dishwasher, but pots, pans, and other stuff that can't go it cost us a huge bottle of dish soap every couple of weeks.